These peanut butter frosted brownies pair rich chocolate with creamy peanut butter. The brownies are moist and chewy with deep chocolate flavor, and the peanut butter frosting is slightly salty, sweet, and silky. Top with Reese’s Pieces or mini peanut butter cups if desired.
This post was updated May 4, 2024 with new photos and recipe tips
If you love chocolate and peanut butter, make these peanut butter frosted brownies. They’re dense, fudgy and chewy, made with both melted chocolate and cocoa powder for a more complex chocolate taste. The brownies are finished with a generous layer of creamy peanut butter frosting — its salty edge balances the brownies’ sweetness for a truly irresistible treat.
For the Chocolate Brownies
This version yields a fudgy, not cakey, brownie. You’ll melt chopped chocolate with butter, then whisk in granulated and brown sugars, eggs, and vanilla. The brown sugar helps create chewiness and enriches the flavor to complement the peanut butter frosting. Fold in the flour, cocoa powder, and salt. The batter is made in one bowl for minimal fuss.
Bake the brownies at 350°F (175°C). Baking time depends on how gooey you prefer them — 25–30 minutes is recommended here. A toothpick inserted at the center should come out clean or with a few damp crumbs, but not coated in raw batter. There’s no baking powder or baking soda in this recipe, which keeps the texture dense and fudgy.
Peanut Butter Frosting for Brownies
After the brownies are fully cooled, prepare a silky peanut butter frosting made from:
- unsalted butter
- smooth peanut butter (avoid natural varieties where oil separates)
- powdered sugar
- vanilla and a pinch of salt
- a splash of milk or cream to reach spreading consistency
Use a smooth, stable peanut butter (not “natural” that separates) to prevent the frosting from breaking. This recipe makes enough frosting for a thick, generous layer — you’ll likely be glad you did.
Tip: Let the brownies cool completely before frosting. Warm brownies will melt the frosting and make it runny.
These brownies are rich and full of flavor. The peanut butter frosting’s saltiness helps temper the sweetness, making each bite balanced and addictive.
Ingredients
Brownies
- 1/2 cup unsalted butter (112 g)
- 5 oz semi-sweet chocolate (142 g), or 50–70% dark, finely chopped
- 1/2 cup granulated sugar (100 g)
- 1/2 cup brown sugar (105 g)
- 2 large eggs, whisked
- 1 tsp vanilla extract
- 1/2 cup all-purpose flour (63 g)
- 1/4 cup cocoa powder (22 g)
- 1/4 tsp salt
Peanut Butter Frosting
- 1/3 cup unsalted butter (75 g), softened
- 1/3 cup smooth peanut butter (do not use natural)
- 1 1/2 – 2 cups powdered sugar (165–220 g)
- 1 tsp vanilla extract
- 1/4 tsp salt
- 1–2 tbsp milk or cream
Equipment
- 8×8 inch (20×20 cm) pan
Instructions
Brownies
- Preheat oven to 350°F (175°C). Line an 8×8 inch pan with parchment paper or aluminum foil, leaving an overhang for easy removal.
- Place butter and finely chopped chocolate in a heatproof bowl. Melt in the microwave on medium power in 45-second intervals, stirring between intervals, until smooth. Alternatively, melt together over a double boiler.
- Let the chocolate mixture cool slightly, then whisk in granulated sugar, brown sugar, vanilla, and the whisked eggs until combined.
- Stir in the flour, cocoa powder (sift if lumpy), and salt until just combined.
- Pour batter into the prepared pan and bake about 25–28 minutes, or until the top is set and a toothpick comes out clean or with a few damp crumbs but no raw batter.
Peanut Butter Frosting
- In a medium bowl, beat the softened butter until smooth, then beat in the peanut butter.
- Add 1 cup powdered sugar, vanilla, and salt. Beat on low, then increase to medium until combined.
- Beat in remaining powdered sugar about 1/2 cup at a time, alternating with 1 tablespoon milk or cream as needed to reach a spreadable consistency.
- Make sure the brownies are completely cool. Lift them from the pan using the parchment overhang and place on a cutting board.
- Frost the cooled brownies. Optionally top with Reese’s Pieces or chopped peanut butter cups. Slice with a thin, sharp knife.
Notes
- Pan sizes: You can double the recipe and bake in a 9×13 inch pan. Bake time will increase to about 30–35 minutes if brownies are thicker.
- Nutrition: Nutrition facts are estimates per brownie if the pan is cut into 16 equal pieces.
- Storage: Store frosted brownies at room temperature in an airtight container for up to 3 days, or refrigerate up to 5 days. Unfrosted brownies freeze well when wrapped tightly; thaw overnight in the fridge before frosting.
Recipe Summary
Servings: 16 brownies
Prep time: 30 mins
Cook time: 25 mins
Total time: 55 mins
