Fudgy Brownie Cupcakes with The Best Peanut Butter Frosting
Ingredients
Brownie Cupcakes:
- 1 cup (227 g) salted butter
- ½ cup (85 g) semisweet chocolate chips
- 1 ½ cups (318 g) lightly packed brown sugar
- 1 tablespoon vanilla extract
- 3 large eggs
- 1 cup (142 g) all-purpose flour
- ¾ cup (64 g) unsweetened cocoa powder
- 1 teaspoon baking powder
- ½ teaspoon salt
Peanut Butter Frosting:
- 6 tablespoons (85 g) salted butter, softened
- ¾ cup (191 g) creamy peanut butter
- 2 cups (228 g) powdered sugar
- Pinch of salt
- ½ teaspoon vanilla extract
- ¼ cup heavy cream, plus more if needed for consistency
- Mini peanut butter cups for garnish, optional
Instructions
- Preheat the oven to 350 degrees F. Line two 12-cup muffin tins with paper liners and set aside (if you only have one muffin tin, you can halve the recipe or bake in two separate batches).
- For the cupcakes, in a large microwave-safe bowl, add the butter and chocolate chips. Microwave for one minute intervals, stirring in between, until the mixture is melted and smooth. Add the brown sugar and vanilla and mix (it will appear grainy; that's ok!). Add the eggs and mix until well-combined.
- In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt. Add to the wet ingredients and mix until just incorporated and no dry streaks remain.
- Divide the batter evenly among the prepared muffin tins, filling the cups about 2/3 full. Bake for 10-12 minutes until they are no longer jiggly in the center (don't overbake or the texture might be crumbly).
- Let the cupcakes cool for a few minutes in the pan before removing them to a wire rack to cool completely.
- For the frosting, in a stand mixer fitted with the paddle or whisk attachment or in a large bowl using a handheld electric mixer, whip together the butter and peanut butter until creamy and smooth, 1-2 minutes. Add the powdered sugar and mix on low speed until it is mostly incorporated. Add the salt, vanilla and heavy cream and mix until light and fluffy, 1-2 minutes, scraping down the sides of the bowl as needed. Add additional heavy cream and whip thoroughly if needed for a softer frosting.
- Frost the cooled cupcakes and garnish with a peanut butter cup, if desired. Store the frosted (or unfrosted) cupcakes in the refrigerator until serving.
Notes
Chocolate: I almost always use Ghirardelli or Guittard semisweet chocolate chips; bittersweet chocolate chips work great in this recipe, too, for a slightly darker chocolate cupcake.
Make-Ahead: these cupcakes can be frosted and made ahead up to 24 hours. I store them in the refrigerator and take them out about an hour before serving (they are pretty delicious eaten chilled, as well).