Root Beer Cake Brownies

by Erin

To make root beer cake brownies, all you need is two ingredients – root beer and brownie mix. With a couple extra ingredients you can also top them with chocolate butterscotch frosting!

Cut Root Beer Cake Brownies.

Jump to recipe

I hope everyone is having a great Labor Day weekend! I’m having a fun time catching up with my now 5 month old nephew in Boston and rejoicing in the start of college football season. I am a little traveling gnome, because I was only home 12 hours before being whisked away again. When I get back I’ll only be home about 3 days before heading out once more for a wedding in Nashville, and then a conference in San Francisco. Wee!

But amidst all this travel, I have not forgotten about my responsibilities. Today marks the 2nd of the month which means another post! Unfortunately 11 years later that website is not longer hosting those recipes so I have taken it upon myself to update them on my own website for safe keeping. Let’s check out these easy two ingredient root beer cake brownies I made for you!

Root Beer Cake Brownies Ingredients.

Two Ingredient Root Beer Cake Brownies

Want to know the simplest way to make brownies? All you need is a box of brownie mix and 12 ounces of your favorite pop — root beer for me! No eggs are needed, not even oil. But don’t be shy about adding your own little extras like butterscotch chips – which makes them more than 2 ingredients but mix-ins are easy!

Versions of this recipe have popped up all over the place, usually with low fat brownie mix and Diet Coke. But I don’t like Diet Coke unless it is concealed by liquor and I couldn’t find low fat brownie mix in the grocery store anymore. So obviously I took the opportunity to use delicious root beer and full-fat brownie mix instead. Of course you could also make root beer brownies from scratch if you prefer.

Bite taken out of Root Beer Cake Brownies.

The first time I made it I used Fitz’s from St. Louis, MO (as you can see in the old photo at the bottom of this post) – if you’ve never been, you need to go, they brew it there and have it on tap in addition to bottles. Obviously I tried both so I could taste it fresh and keep a bottle for my root beer collection.

The second time around I chose Stewart’s because it was National Stewart’s root beer day – why they get their own day and generic root beer does not is beyond me, but here we are.

Root Beer Cake Brownies.

When I made this recipe, the batter was more of a cake batter consistency than brownie batter – likely due to the added leavener due to the bubbles. As a result, most of the butterscotch pieces fell to the bottom. Regardless, I still nearly inhaled the entire pan of these root beer cake brownies after one bite. I forced myself to brush my teeth after finishing the second piece to prevent myself from going on an eating marathon.

Just like the uncooked batter, these brownies are more like cake brownies because they are are not quite as fluffy as a cake but not quite as dense as a brownie – again likely due to the added carbonation. However they still taste like a brownie with root beer flavors. Happy surprise as the base of this recipe went on to inspire my root beer float brownie cupcakes.

Root Beer Cake Brownies in hand.

How do you make brownies less cakey?

Fudgy brownies have a higher fat-to-flour ratio than cakey ones. So if you wish for a more typical consistency for these root beer brownies you would need to add more fat to the recipe – such as butter and chocolate. This could combat the added leavener from the root beer bubbles, but it also strays away from the concept of making two-ingredient root beer brownies.

But then I decided to throw all that minimal ingredient talk our the window because I went and topped these root beer cake brownies with frosting! I guess adding the one extra in the form of butterscotch chips was enough to open the flood gates. I thought about adding root beer in the frosting as well, but decided to stick to the butterscotch flavor accent paired with chocolate. The end result enhances the root beer flavors, resulting in an even superior brownie.

Post updated 6/17/2023, photo above is the original.

Cut Root Beer Cake Brownies.


Yield: 16 Servings Prep Time: Cooking Time:
Nutrition facts: 200 calories 20 grams fat



  • 1 box brownie mix
  • 12 oz. root beer
  • 1/2 cup butterscotch chips (optional)


  • 1 oz. butterscotch chips
  • 1/4 cup (4 Tbsp) unsalted butter, room temperature
  • 1/2 tsp salt
  • 1/3 cup unsweetened cocoa powder
  • 1-1/4 cups powdered sugar
  • 2 Tbsp milk


  1. Preheat oven to 350°F. Line an 8-inch baking pan with foil or parchment paper and spray with non-stick spray.
  2. In a large bowl, blend brownie mix and root beer together until just incorporated (do not over mix). Stir in the butterscotch chips, if using.
  3. Pour batter into prepared baking pan. Bake for about 25-30 minutes, or until an inserted toothpick comes out clean. Allow to cool completely before frosting.
  4. While the brownies cool, place butterscotch chips and one tablespoon of butter in a small microwave-safe bowl. Heat in 15 second intervals, stirring in between, until fully melted. Set aside to cool.
  5. In a medium bowl, beat the remaining three tablespoons of butter and salt. Add cooled butterscotch mixture and blend. Add cocoa powder and powdered sugar and beat until smooth. Add milk one tablespoon at a time to reach your desired consistency.
  6. Frost bars once cooled and cut into 16 squares.
Did You Make This Recipe?
I want to see! Tag me on Instagram at @TheSpiffyCookie and hashtag it #TheSpiffyCookie.

Source: Brownies adapted from Dinners, Dishes, and Desserts. Frosting adapted from Brown Eyed Baker.

One year ago: Biscoff Cheesecake Ice Cream

Did you make this recipe? I want to see! Tag @THESPIFFYCOOKIE on Instagram and hashtag it #THESPIFFYCOOKIE

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Root Beer Float Brownie Cupcakes July 20, 2020 - 11:49 am

[…] Cupcakes adapted from my Root Beer Cake Brownies, frosting from my Cone Head Cupcakes with Ice Cream […]

sally @ sallys baking addiction September 4, 2012 - 1:31 pm

so glad you’re apart of too, Erin! I just checked these out — amazing! I never thought to add root beer to a brownie mix before? Crazy!

Jessica@AKitchenAddiction September 4, 2012 - 12:11 pm

This sounds like a great combo!

Baker Street September 4, 2012 - 7:44 am

I love frosted brownies and these look absolutely fantastic!

Jennifer @ Peanut Butter and Peppers September 2, 2012 - 10:26 pm

Thats different! I have to check it out!!

Stephanie @ Eat. Drink. Love. September 2, 2012 - 9:42 pm

I have been wanting to try this! So easy!

Erin @ Dinners, Dishes and Desserts September 2, 2012 - 4:34 pm

Oh yum! I love rootbeer, and I love frosting on brownies – these look so good!


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