Chocolate Peanut Butter Buttercream

Pan of brownies with chocolate frosting and Reese's cups

My friends and I have a weekly gathering for Taco Tuesday at the local bar. I’d like to call it a pub, cause that sounds fancier, but it’s really just the local watering hole that has cheap tacos on Tuesdays. They are garbage tacos. For real. I could not even recommend eating them to someone I don’t like.

But, the other food is decent and cheap and they don’t care if we spend two hours talking and laughing and catching up on our week. It’s fantastic because we all know there will be someone to have dinner with on Tuesday at 7 p.m.

pan of brownies with chocolate peanut butter buttercream topped with mini Reese's cups

Somewhere along the path, we started making brownies for birthday celebrations of the Taco crew. They aren’t usually fancy, just a box of brownie mix with a few handfuls of chocolate chips thrown in. (It is a weeknight after all). It isn’t even always the same person that brings them. But the point is, we love each other enough to make it a point to bring something homemade (even if only barely) to celebrate each other’s lives.

Hand sprinkling mini Reese's cups onto pan of brownies

This week, I found myself with a spare 15 minutes so I decided to frost these brownies with a decadent chocolate peanut butter buttercream. Heavy cream in the frosting whips up to give a fluffy, creamy texture to contrast nicely with the density of the brownies. And then, mini Reese’s just because.

There’s no recipe for the brownies, because I simply used a box mix from my pantry. This frosting whips up in less time than it takes the brownies to bake. You can have your whole dessert complete in under an hour. Kind of. You do need to let your brownies cool before frosting or you will have a nice frosting puddle on top.

I also think this buttercream would really shine when used with this chocolate cake recipe. Just be sure to double the recipe to have enough.

Chocolate Peanut Butter Buttercream

Creamy, chocolatey peanut butter buttercream frosting.  Perfect for topping your favorite chocolate or peanut butter dessert.
Course Dessert
Keyword frosting
Servings 1 9×13″ pan of brownies
Author Heather


  • 1/2 cup salted butter softened
  • 1/2 cup creamy peanut butter don’t use natural
  • 1 teaspoon pure vanilla extract
  • 1/2 cup cocoa powder
  • 4 cups powdered sugar
  • 1/2 cup heavy cream
  • 1/4 cup water for thinning, may use more


  • If using a stand mixer, fit with paddle attachment.
  • Cream together butter and peanut butter until well combined and fluffy.
  • Drizzle in vanilla extract.
  • With the mixer on it’s slowest possible speed, SLOWLY add in cocoa powder and powdered sugar.  The mixture is going to get SUPER thick.  Drizzle in some water (2-3 tablespoons) to keep everything smooth
  • Add in heavy cream and beat on high speed for a minute or two.  This whips up the heavy cream and gives the frosting a little more “fluff”
  • If the frosting is still to thick, add in more water-1 tablespoon at a time, until the desired consistency is reached.  I like a really spreadable frosting so I used the whole 1/4 cup of water but if you are planning to pipe anything with it, you don’t want to add as much water.