
Fudgy brownie cupcakes covered in creamy peanut butter frosting.
What is happening?? Has it really been over a MONTH since my last peanut butter recipe?!?? So shameful.
Let’s just make up for that disgrace with an over-the-top, yet completely simple brownie cupcake. The cupcake itself is so fudgy and rich, that I could almost just eat it plain. But I knew these fudgy brownie cupcakes were the perfect dessert canvas for peanut butter.
This frosting! Be still my heart. I originally planned to top these fudgy brownie cupcakes with cream cheese frosting, but let’s be serious. I immediately reached for the peanut butter jar after the cupcakes cooled. It’s a simple frosting recipe, really. And my secret ingredient is the heavy cream.
Trust me on this. Heavy cream is a frosting’s dream come true. It creates the smoothest, fluffiest frosting on earth. Plus, it makes the frosting so easy to pipe or slather on the cupcake. And yes. It is impossible not to swipe a taste from the frosting bowl.
If you’re loving this spin on brownies, be sure to try my brownie cupcakes with cookie dough frosting next.
Sidenote: I used a Wilton 1M piping tip to frost these. Feel free to just swirl the frosting on with a knife or use another piping tip. I love the 1M though… it creates pretty swirls like a soft serve ice cream cone!

Brownie Cupcakes with Peanut Butter Frosting Recipe
Ingredients You’ll Need
Instructions
- Preheat oven to 375°F (191°C). Line a 12-count muffin pan with cupcake liners.
- Melt butter in the microwave in a large microwave safe bowl. Mix in the sugar until smooth and microwave for about 1 minute. Stir the mixture until smooth again. Whisk in the vanilla and eggs. In a separate bowl, mix together the salt, baking powder, cocoa powder, and flour. Slowly add to the wet ingredients and stir until completely combined.
- Fill the muffin tins about 2/3 full. Bake in the prepared muffin tin for about 8-10 minutes (mine took a little under 9 minutes). Allow to cool completely.
- Using an electric handheld mixer or stand mixer fitted with the paddle attachment, beat softened butter on medium speed for 1 minute until completely smooth and creamy. Add the peanut butter and beat on medium-high speed until the two are combined. Add the confectioners’ sugar, cream, vanilla extract, and salt. Beat on low speed for about 20 seconds, then gradually increase to high speed. Beat on high for 1 minute. Frost cooled cupcakes. Top with chocolate sprinkles, if desired.