Guest Post: Peanut Butter Fudge Cake by Bake or Break

by Erin

Chocolate cake and chocolate icing surround a layer of peanut butter. As good as that sounds, the whole is actually much greater than the sum of its parts.

Peanut Butter Fudge Cake

Jump to recipe

Jennifer may not know it, but we go way back. When I first started reading food blogs (pre-The Spiffy Cookie), one of the first food blog recipes I made was from her blog, Bake or Breakchocolate chip cookie dough cheesecake bars.

After nearly 3 years of food blogging it’s a crying shame that I have not made them again. But with all her marvelous recipes, such as lemon blueberry cheesecake bars and chocolate chunk pecan cookies, it’s hard to keep up!

However, I have made a few other of her recipes that involve the notorious PBC (peanut butter and chocolate).

In case you hadn’t noticed, Jennifer shares my appreciation for the combination of peanut butter and chocolate, and within the first two months of my own food blogging adventures I posted about one of her pb+choc recipes – brownie peanut butter cups (go ahead and judge my picture, despite the glorious ooze of peanut butter).

Also during last year’s football season I adapted another recipe or hers to make my Buckeye monkey bread muffins. It seems extremely appropriate that she is sharing a recipe for peanut butter fudge cake today – I totally approve!


Hello, dear readers of The Spiffy Cookie! I’m Jennifer from Bake or Break. While Erin is toiling away on the final days of her dissertation adventure, I’m here to talk about cake. That seems absolutely appropriate, right?

I thought so.

Plus, it’s peanut butter and chocolate. I think Erin will approve.

Peanut butter and chocolate are, for me, the ultimate flavor combination. Sure, I like and even adore other combos, but this one is near and dear.

The premise of this cake is pretty simple. Chocolate cake and chocolate icing surround a layer of peanut butter. As good as that sounds, the whole is actually much greater than the sum of its parts.

The cake and icing are very much reminiscent of a Texas Sheet Cake, with some stovetop cooking involved for both. The chocolate cake is moist and soft and just lovely. It has a nice, delicate chocolate flavor. That’s a good thing, because the icing is not even remotely subtle in the chocolate department.

Peanut Butter Fudge Cake Slice

The peanut butter filling couldn’t be simpler. It’s peanut butter. Seriously. Spread it on the cake while it’s still warm, and the peanut butter will make a lovely, tasty layer between the cake and the icing.

I love this kind of icing. It’s simple to make, so that’s always a plus. And, it’s so soft and gooey. It goes on the cake while it’s warm, and then it hardens and sets as it cools. It forms some kind of serious shield over the cake. Don’t be alarmed if the icing cracks and crinkles when you cut into it. That’s just the nature of this kind of icing. If it bothers you, that’s why some very smart person invented garnishes.

This cake certainly qualifies as a crowd-pleaser. First of all, it makes enough for a crowd. Secondly, it’s chocolate and peanut butter, so what’s not to like?

Recipe adapted from Southern Living


Yield: 24 servings
Nutrition facts: 200 calories 20 grams fat


For the cake:

  • 2 cups all-purpose flour
  • 2 cups granulated sugar
  • 1 teaspoon baking soda
  • 1 cup unsalted butter
  • 1/4 cup unsweetened cocoa powder
  • 1 cup water
  • 1/2 cup buttermilk
  • 2 large eggs, lightly beaten
  • 1 teaspoon vanilla extract
  • 16 ounces (about 1 & 1/2 cups) creamy peanut butter

For the icing:

  • 1/2 cup unsalted butter
  • 1/3 cup buttermilk
  • 1/4 cup unsweetened cocoa powder
  • 16 ounces confectioners’ sugar, sifted
  • 1 teaspoon vanilla extract


  1. Preheat oven to 350°. Grease and flour a 9” x 13” baking pan.
  2. Whisk together flour, sugar, and baking soda in a large bowl. Set aside.
  3. Place butter in a medium saucepan. Melt over medium heat.
  4. Stir in cocoa powder. Then, stir in water, buttermilk, and eggs. Continue cooking over medium heat, stirring constantly, until the mixture boils.
  5. Remove the mixture from the heat and add to flour mixture. Stir until smooth. Stir in vanilla.
  6. Transfer batter to prepared pan and spread evenly.
  7. Bake 20 to 25 minutes, or until a pick inserted into the center of the cake comes out clean.
  8. Cool in pan on wire rack for 10 minutes. Then, spread the peanut butter over the cake. Allow to cool completely.
  9. To make the icing, place the sifted confectioners’ sugar in a large bowl. Set aside.
  10. Combine butter, buttermilk, and cocoa in a small saucepan. Cook over medium heat, stirring constantly, until the mixture begins to boil.
  11. Remove from heat and pour over confectioners’ sugar. Stir until smooth. Stir in vanilla.
  12. Spread icing over peanut butter. The cake can be served immediately or can sit at room temperature to allow the icing to set.
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Tammy Mojica March 5, 2023 - 2:30 am

Going to make this cake !!!!

Rebecca L Thompson July 30, 2021 - 5:25 pm

This is awesome! I veganized it with flax eggs, oatmilk, and Crisco. Worked like a dream.

Erin July 31, 2021 - 10:14 am

Nice! Thanks for commenting so that others know it works!

Tamara Nikolajew December 3, 2020 - 8:41 am

Great recipe and so tasty!! My eggs did curdle when I added it to the pot. I simply strained it and it turned out fine. Will make again. Thank you

Christy September 6, 2020 - 12:22 pm

My using was too thin, so I just swirled in with the peanut butter. Putting in freezer to set.

Darlene Willkomm February 11, 2017 - 10:30 am

Yes, you do NOT mix the eggs into the hot mixture, You mix them with the flour mixture first!

Aj November 6, 2016 - 10:07 pm

I’ve made this 5 times in the past 10 months – we LOVE it!

After the first time, I made 3 minor adjustments:
1. I add 1 level teaspoon of instant coffee to the melting butter for the cake. You can’t taste the coffee, it only deepens the chocolate flavor.
2. I mix together the water, buttermilk and egg, then add them to the butter and chocolate in the pan. I’ve never had a problem with egg lumps.
3. I whip the peanut butter for a few minutes – that makes it lighter, fluffier, and warms it just a bit – I can drizzle it on the cake instead of dollop and spread.

This is now the most requested cake at our house – thank you! :)

Morgan April 15, 2016 - 4:00 pm

Could you make this In a shallow baking pan instead of 9 x 13? Thinking 12 x 15 or so.

spiffycookie April 15, 2016 - 4:21 pm

Morgan, I’d have to ask Jennifer but I don’t see why not. Just reduce the baking time!

Francine November 22, 2015 - 3:05 pm

I think there’s a mistake in the icing recipe…should probably one quarter cup of butter not half… mine came out liquid. Tried a new batch but for some reason the buttermilk curdled. So tasted it w only peanut butter… that’s all I could taste so scrapped off to see what cake was like…. ok but chocolate taste very mellow. Not worth it.

Francine November 22, 2015 - 2:10 pm

Hi, the icing came out liquid…i even added more conf. Sugar….still liquid. What’s going on?

Jennifer | Bake or Break November 22, 2015 - 8:27 pm

Hi, Francine. If you made no changes or alterations to the recipe (even low fat ingredients), then my guess is that the cooked mixture didn’t quite get cooked enough to thicken. Try letting it boil for a minute or so before removing it from the heat.

Marcia S. September 8, 2015 - 10:41 pm

I love this recipe! I have made it many times, my family loves it! Thanks for posting!

kris h August 2, 2015 - 8:46 am

You may want to add a note about tempering the eggs or inexperienced cooks will end up with chocolate scrambled eggs.

sally February 28, 2015 - 4:45 pm

The icing does not work with only 16 oz. Of confectioners sugar….way too watery with only that much!

Sarah June 9, 2014 - 11:27 am

Looks great! Do you think I can half it and make an 8×8 cake?

charlie barrett March 15, 2014 - 2:02 pm

I’ve made a few of these all turned out great and was a hit with everyone that tried it….however this time apparently the icing boiled to hot or long or something…it set up like wood putty instantly in the powdered sugar, impossible to spread, maybe it’ll taste ok. be careful of boiling time……JESUS LOVES YOU!!!….just sayin.

Peg January 26, 2014 - 5:57 pm

Not a good idea to put mixed egg into hot liquid. Had to strain out the egg whites that made a scrambled eggs in the batter. Would have just melted butter and added that to the overall mixture. It’s in the oven but I hope it works out.

Cassie February 2, 2014 - 12:10 pm

I thought the same thing but tried it anyway and one it cooks you don’t notice it. Just make sure to keep stirring when it’s on the stove top!

Sheryl Sims January 22, 2014 - 12:18 pm


Joyce January 21, 2014 - 9:27 pm

Made this for our cook out it went over great got calls for recipe gave it a 5 star loved it

Kristin January 20, 2014 - 1:25 pm

Am trying this today for my daughters 18th birthday! She is gluten free so I am using a GF cake mix since those cakes tend to be on the dense side anyway. I was so excited to see the idea for the frostings as she LOVES peanut butter!

Desiree January 19, 2014 - 1:21 pm

It came out great! :)

Desiree January 19, 2014 - 12:08 pm

Hi all! I just mixed this up, but.. i put the peanut butter in with the melted ingred. It was listed under the cake ingred. so I should have read the directions first! Well I will let you know shortly how it turns out, either way I bet it will be delish!

Kim January 18, 2014 - 2:19 pm

I could see small pieces of egg as I was cooking the mixture. Is that supposed to happen?

Jessie January 18, 2014 - 1:21 pm

I wonder if you poked holes in the cake (like you would do for a jello poke cake) and then spread peanut butter of the cake would work? That was the flavor of the peanut butter would blend more with the chocolate

saundra January 18, 2014 - 1:19 pm

egg should never be mixed with hot liquid untill mixing thoroughly first.

saundra January 18, 2014 - 1:19 pm

egg should never be mixed with hot liquid untill mixing thoroughly first.

charlie January 18, 2014 - 12:11 pm

I got one setting with pb on it another ready to come out of the oven, one for the family and one for the youth at Church tomorrow morning. I can’t wait.

charlie January 18, 2014 - 11:57 am

looked good…..i’m making one today for me and my family and one for the youth class at tomorrows Sun. school class. I can’t wait to try it. I got one cooling with pb on it and the other in the oven.

Laura January 18, 2014 - 9:34 am

I love the sounds and look of the chocolate peanut cake. Can you tell me how to make it all sugarfree and still taste good??

Kati February 6, 2014 - 12:55 am

you can use Agave Syrup to replace sugar or honey. To replace sugar try substituting 1/4 to 1/2 cup for every cup of sugar. Also you will need to reduce the same amount of liquid. Add the agave with the fat or liquid. If you are substituting for honey just use the same amount.
So this particular recipe calls for 2 cups of sugar. Try using 1/2 cup at first, (if you find later that this isn’t sweet enough you can increase it to as much as 1 cup) Reduce the water to 1/2 cup, and add the agave syrup with the water and buttermilk. If you need to increase the agave to 1 cup just eliminate the water. I would leave the buttermilk for the richness and acidic quality.
As for the frosting you could try using a mixture of cornstarch (tablespoon or two), powder sugar substitute such as stevia or equal, a few packets, and powdered milk(enough to make up the bulk of the powdered sugar needed for the recipe. If you need it thicker add a little more cornstarch, if it’s too thick add some more liquid. I would highly recommend using the powdered sugar substitute for the frosting.

Becky January 17, 2014 - 9:35 am

Made this today, and definitely had egg pieces in the batter..pretty sure if I make this again I will temper the eggs first…wish I would have thought of that in time this time.

Katherine January 16, 2014 - 7:41 pm

Looks delicious. This is the basically a Texas sheet cake recipe. Exact same ingredients. I have made it many times and the instructions are a bit different and there is not be any problem with eggs this way. Comes out great and is so easy. I love this peanut butter variation and will try it.

Instructions: In large bowl, combine sugar, flour, cocoa powder, baking soda and salt; set aside. In small saucepan, bring butter and 1 cup water to a boil; stir into sugar mixture, Whisk in buttermilk, eggs and vanilla until thoroughly blended. (I just whisk by hand because it is so easy and fast, mixer not required) Pour batter into prepared pan (batter will be thin and silky). I make in a 15×10 pan and bake 20 min at 400 degrees. Makes a lot for crowd and good cake to frosting ratio ;-)

If you make in larger sheet pan, you will need more frosting. I use this CHOCOLATE FROSTING recipe. Very similar, just more sugar.

4 cups C&H Powdered Sugar
1/2 cup butter or margarine
1/4 cup unsweetened cocoa powder
6 tablespoons milk

In large bowl, combine sugar and walnuts; set aside. In small saucepan, bring butter, cocoa powder and milk to a boil. Stir into sugar mixture; blend thoroughly. Spread on warm cake.

Mel February 26, 2014 - 5:35 am

What walnuts? I don’t see them in the ingredients – only in the instructions. Am I missing something?

Serena January 16, 2014 - 8:34 am

Made this yesterday for my husband. Wish I could eat it but, you know, new year resolutions and all. He loves it. I added chocolate chips to the peanut butter for a little crunch and well its chocolate, lol. It is husband approved. He loves it. ;)

Kelly January 15, 2014 - 10:16 pm

It looked like my batter had been mixed with egg drop soup. The egg cooks into chunks when you mix it into the butter mix on the stove. Should the eggs maybe be added later? It just seems odd. It is baking right now, so it remains to be seen how mine turns out, but I am a little weirded out by the eggs.

David January 19, 2014 - 4:26 pm

That happened to me too. I was wondering how your cake turned out. Mine is still cooling. I didn’t see anyone that answered your question, hopefully we didn’t do something wrong. lol…

Alyshia January 20, 2014 - 4:56 pm

When I make this I add the eggs after I mix the chocolate mixture with the flour mixture. No eggs to the boiling pan, I thought it might make scrambled eggs too so I waited to add the eggs! Then I add the vanilla and it turns out great

Kati February 6, 2014 - 12:09 am

You should have effectively cooled down the butter and coco powder when you stirred in the water and buttermilk. Then quickly stir in the beaten eggs. the water and buttermilk don’t say you have to have room temp so I would add it cold. You have to bring it back to a boil anyway. Think of this stage as almost a pudding.

Susan February 20, 2014 - 7:45 pm

I make a cake very similar to this, but my recipe says to sift the dry ingredients, except the soda.Then bring to boil the water, cocoa, and butter and pour over the dry ingredients. Mix the soda, buttermilk, eggs and vanilla together and stir well (the soda will react with the buttermilk, so use a bowl about twice the size of the ingredients). Then add that to the above mixture, beat until there are no lumps, and bake as directed. Works perfectly.

Emily July 26, 2015 - 5:54 pm

Kelly, that happened to me too at first. I ended up throwing it out, and making a new batch. The only thing I did differently was I put the butter in the pan to melt, and while it was melting I combined the water, buttermilk, and eggs. I made sure I stirred it together well. Then I put my mixture through a sifter, and it got out any egg I didn’t mix in all the way. Then I put in the cocoa powder, stirred that in good, and finally put in the water, buttermilk, and egg mixture. After it started to boil (which took a while on medium heat) I ran the butter, cocoa powder, water, egg, and buttermilk mixture through a sifter one more time and it got out little pieces of egg that it missed the first time. It had hardly any egg in it this time, and when i sifted it again in got out all of the extra. I hope this helps, and happy baking!

Libby January 10, 2021 - 1:31 pm

After I added the mixture to the dry ingredients I added the eggs and vanilla then mixed it well. The egg whites will lump if you try to cook them with the butter and milk.

Jennifer January 13, 2014 - 11:09 am

Can you replace the buttermilk with something else? Maybe sour cream?

spiffycookie January 13, 2014 - 11:14 am

If you don’t have buttermilk, you can add 1 tablespoon of white vinegar or lemon juice to 1 cup of regular milk. You could use sour cream or yogurt but it will be thicker if you replace 1:1 so I would do half milk half sour cream/yogurt if you want to go that route.

Jennifer January 13, 2014 - 11:36 am

Thank you so much for that info!! (sorry if I bombarded you with messages, I tried commenting using my phone and it wasn’t showing up so I resorted to getting on the computer to submit. I think it might have sent all messages before I realized it! So sorry!

Corrine January 13, 2014 - 9:32 am

I am so going to try this, it looks like a really yummy chocolate fix for sure!!!

Cmk1975 January 12, 2014 - 11:41 am

Attempting now….praying it turns out!!!!

Shelva January 11, 2014 - 5:28 pm

If you follow this very simple recipe you can’t go wrong. The cake will turn out perfect. I don’t understand.

Beth Cranford January 10, 2014 - 12:39 pm

Oh my! I just found this on Yumprint (which I just found out about) I must make this today!

spiffycookie January 10, 2014 - 4:34 pm

I’ve never heard of Yumprint. I will have to check it out.

Tara December 5, 2013 - 1:31 pm

My batter looks like it has egg pieces in it???

brittany October 4, 2013 - 7:11 pm

oh and my icing came out runny :(

brittany October 4, 2013 - 7:03 pm

how did you get it to turn out so pretty? i just pulled mine out of the oven and put it on the pan to cool and it completely fell apart and it took almost an hour to cook so i dont know if i put too much of something in to make the batter or not enough? i followed it the best i could and it just fell apart

Vicky January 16, 2014 - 8:05 am

Sounds like your baking powder was bad!

DT September 29, 2013 - 8:57 pm

I made this for a potluck and it was fantastic! I was a bit skeptical mixing it up, but it was great. It’s very rich – a small piece is perfect. Thank you so much for sharing!

Melody September 23, 2013 - 10:30 pm

I want to make this but I have to ask, you just spread the peanut butter (right out of the jar) onto the cooling cake? It doesn’t tear the cake? Does it spread easily?

Jennifer | Bake or Break September 26, 2013 - 9:34 am

Hi, Melody. Yes, the peanut butter goes straight onto the warm cake. I dolloped all of it on, and the heated up the peanut butter a bit, making it very easy to spread. I didn’t have any issues with the cake tearing. If it should tear a little, it has a layer of peanut butter and a layer of frosting on top of it, so it won’t be visible. I hope you like the cake!

Melody September 26, 2013 - 9:46 am

Thank you Jennifer. I feel certain that I will enjoy it! :)

Sanaya Anson September 20, 2013 - 1:05 am

Delicious Cake I just loved your recipe. Peanut butter and cake both are my favorite, so this is the favorite of mine.

Terese @ September 19, 2013 - 10:19 pm

It does look very tasty, and the picture is wonderful! Makes it look so yummy! Will definitely try it, just have to find the right time to do it.

Candi September 12, 2013 - 6:18 pm

Anybody make it yet? Details I want details!!!! I think it must be divine!

Michele Donisi March 19, 2014 - 3:26 pm

I made this twice! Everyone goes crazy over it! I brought it to work and they were fighting over it! Passing the recipe out to all who request it – it’s too good not to share!

Emily @ Life on Food September 12, 2013 - 5:51 pm

Chocolate and peanut butter is the best! Best, Best! This cake looks tremendous!

Lucy @ Lucyeats September 12, 2013 - 3:05 pm

Omg anything chocolate + peanut butter has me salivating. I love the look of this fudge cake, absolutely perfect!

Javi Trulove @T3treats September 12, 2013 - 12:43 pm

Awww it must taste like heaven.. i never in my life have tried Peanut butter but maybe i can try to find a little to make this awesome recipe

spiffycookie September 12, 2013 - 12:57 pm

Never had peanut butter?! That blows my mind.

Lauren at Keep It Sweet September 12, 2013 - 11:52 am

This looks so completely addicting in a very, very good way. Love this post from Jen!

ATasteOfMadness September 12, 2013 - 9:19 am

Wow, best combination ever. I love the look of the icing on this cake, yum!!

Kayle (The Cooking Actress) September 12, 2013 - 8:28 am

Pb & Choc are def. THE flavor combo. I’m obsessed with this cake and want a piece and it’s not even 10 yet you guysssss.


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