I can’t think of a better party dessert than fudgy brownies piled high with creamy peanut butter frosting. One bite and you’ll see why these disappear fast at every potluck, tailgate, and family gathering.

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I’m completely obsessed with these Peanut Butter Frosted Brownies because they hit that rich, fudgy, peanut-butter-loaded craving without pretending to be fancy. The brownie base is deep and chocolatey from semisweet chocolate, and then that thick layer of creamy peanut butter frosting comes in like it owns the whole pan.

And honestly? It does.

I love bringing these to parties, potlucks, tailgates, basically anywhere people hover near the dessert table. They slice up messy in the best way, taste even better after sitting a bit, and disappear fast.

But if I’m being real, I always save a corner piece for myself.

Ingredients

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Butter makes the brownies rich, fudgy, and honestly hard to stop eating.
Semisweet chocolate brings that deep, melty chocolate bite you actually crave.
Sugar keeps things sweet and gives the tops that classic brownie crackle.
Eggs hold everything together and make the texture chewy, not cakey.
Vanilla adds warmth, like a tiny background hug.
Cocoa powder doubles down on the chocolate, so these don’t taste weak.
Flour gives structure, but not too much, because fudgy is the goal.
Salt keeps the sweetness in check and makes the chocolate pop.
Peanuts or chocolate chips add crunch, pockets of chocolate, or both.
Peanut butter frosting is creamy, salty-sweet, and totally the main event.
Powdered sugar makes the frosting fluffy and sweet without feeling gritty.
Plus, milk or cream helps it spread like a dream.
Basically, that tiny pinch of salt makes the frosting taste like candy.

Ingredient Quantities

For the brownies:

1/2 cup unsalted butter (1 stick)

4 ounces semisweet chocolate, chopped

1 cup granulated sugar

2 large eggs

1 teaspoon pure vanilla extract

1/3 cup unsweetened cocoa powder, sifted

1/2 cup all purpose flour

1/4 teaspoon fine salt

Optional: 1/2 cup chopped peanuts or chocolate chips

For the peanut butter frosting:

1/2 cup unsalted butter, softened

1 cup creamy peanut butter

2 to 2 1/2 cups powdered sugar, sifted

2 to 3 tablespoons whole milk or heavy cream

1 teaspoon pure vanilla extract

Pinch of fine salt, to taste

How to Make this

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1. Preheat oven to 350°F. Line an 8×8 inch baking pan with parchment paper or grease it and set aside.

2. In a heatproof bowl over simmering water or in short bursts in the microwave, melt 1/2 cup unsalted butter and 4 ounces chopped semisweet chocolate together, stirring until smooth; cool slightly.

3. Whisk 1 cup granulated sugar into the melted chocolate mixture, then whisk in 2 large eggs one at a time and 1 teaspoon pure vanilla extract until combined.

4. Sift and add 1/3 cup unsweetened cocoa powder, 1/2 cup all purpose flour, and 1/4 teaspoon fine salt to the chocolate mixture; fold gently just until no streaks of flour remain.

5. Fold in optional 1/2 cup chopped peanuts or chocolate chips if using. Pour batter into the prepared pan, smoothing the top.

6. Bake 20 to 25 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs but not wet batter. Cool completely in the pan on a wire rack.

7. While brownies cool, make the frosting: beat 1/2 cup softened unsalted butter with 1 cup creamy peanut butter until smooth and creamy.

8. Gradually add 2 to 2 1/2 cups sifted powdered sugar, beating on low until incorporated, then add 2 to 3 tablespoons whole milk or heavy cream as needed to reach spreadable consistency. Mix in 1 teaspoon pure vanilla extract and a pinch of fine salt, tasting and adjusting salt or sugar as desired.

9. Spread the peanut butter frosting evenly over the cooled brownies. For cleaner slices chill the frosted brownies 30 minutes to set the frosting.

10. Lift brownies from the pan using the parchment, slice into squares, and serve. Store leftovers covered at room temperature for 2 days or refrigerated for up to 5 days.

Equipment Needed

1. Oven
2. 8×8 inch baking pan
3. Parchment paper or nonstick spray
4. Heatproof bowl for melting chocolate
5. Small saucepan for a double boiler or to heat water
6. Mixing bowl
7. Whisk
8. Rubber spatula or silicone scraper
9. Electric hand mixer or stand mixer for frosting
10. Wire cooling rack

FAQ

How do I know when the brownies are done?

The edges should be set and a toothpick inserted near the center should come out with a few moist crumbs but not wet batter. They will firm as they cool.

Can I use crunchy peanut butter instead of creamy for the frosting?

Yes. Crunchy will add texture and a slightly drier consistency, so you may need an extra tablespoon of milk or cream to reach a spreadable texture.

How should I store these brownies?

Store in an airtight container at room temperature for up to 3 days. Refrigerate for up to 7 days but bring to room temperature before serving for best texture. For longer storage freeze unfrosted brownies for up to 3 months, thaw, then frost.

Can I swap the semisweet chocolate for cocoa powder only?

You can, but you will need to replace the melted chocolate with an equal amount of butter and additional sugar to maintain richness. The recipe as written is best for texture and flavor.

How do I get a smooth, spreadable peanut butter frosting?

Beat softened butter and peanut butter until creamy, then add powdered sugar in batches. Add milk or cream one tablespoon at a time until smooth, and finish with vanilla and a pinch of salt to balance sweetness.

Can I add mix ins like chopped peanuts or chocolate chips?

Yes. Fold up to 1/2 cup of chopped peanuts or chips into the batter before baking. For an even distribution, toss mix ins with a teaspoon of flour first.

Peanut Butter Frosted Brownies Recipe Substitutions and Variations

Unsalted butter (for brownies or frosting):
- Equal amount salted butter, omit or reduce added salt in recipe
- Vegetable shortening, same measure, yields a slightly firmer texture
- Coconut oil, measure-for-measure, adds mild coconut flavor
Semisweet chocolate (for brownies):
- Bittersweet or dark chocolate, same weight, slightly less sugar
- Milk chocolate, same weight, for a sweeter, milder brownie
- Unsweetened chocolate plus 2 to 3 tablespoons sugar, to balance bitterness
All purpose flour:
- Whole wheat pastry flour, use 1 to 2 tablespoons less, yields nuttier flavor
- Gluten free 1-to-1 flour blend, substitute cup for cup, use a blend with xanthan gum
- Almond flour, replace up to half the flour and reduce baking time slightly, makes denser crumb
Creamy peanut butter (for frosting):
- Natural peanut butter, stir well and taste for salt, may need extra powdered sugar for firmness
- Almond butter, same measure, gives a milder, slightly sweeter taste
- Sunflower seed butter, equal substitute, nut free and similar texture

Pro Tips

1. Warm the chocolate and butter slowly and stir constantly until silky. If you see any tiny unmelted bits, keep stirring off the heat for a minute or two so the residual heat finishes the job without cooking the eggs later.

2. Trust the toothpick test but aim for a few moist crumbs rather than completely clean. Pull the brownies out a minute or two early if the center still looks jiggly, because they will finish setting as they cool.

3. Cool completely before frosting. Warm brownies will make the frosting slide and soak in. If you want neat slices, refrigerate the frosted pan for about thirty minutes before cutting.

4. Balance the frosting by tasting as you go. If your peanut butter is very salty, add the lower amount of powdered sugar and a splash more cream for spreadability. If it is mild, add a pinch of fine salt to make the peanut flavor pop and use the higher amount of sugar for structure.

Peanut Butter Frosted Brownies Recipe

Recipe by Tina Bueller

0.0 from 0 votes

Servings

servings

Calories

538

kcal

Equipment: 1. Oven
2. 8×8 inch baking pan
3. Parchment paper or nonstick spray
4. Heatproof bowl for melting chocolate
5. Small saucepan for a double boiler or to heat water
6. Mixing bowl
7. Whisk
8. Rubber spatula or silicone scraper
9. Electric hand mixer or stand mixer for frosting
10. Wire cooling rack

Ingredients

For the brownies:
1/2 cup unsalted butter (1 stick)
4 ounces semisweet chocolate, chopped
1 cup granulated sugar
2 large eggs
1 teaspoon pure vanilla extract
1/3 cup unsweetened cocoa powder, sifted
1/2 cup all purpose flour
1/4 teaspoon fine salt
Optional: 1/2 cup chopped peanuts or chocolate chips
For the peanut butter frosting:
1/2 cup unsalted butter, softened
1 cup creamy peanut butter
2 to 2 1/2 cups powdered sugar, sifted
2 to 3 tablespoons whole milk or heavy cream
1 teaspoon pure vanilla extract
Pinch of fine salt, to taste

Directions

Preheat oven to 350°F. Line an 8×8 inch baking pan with parchment paper or grease it and set aside.
In a heatproof bowl over simmering water or in short bursts in the microwave, melt 1/2 cup unsalted butter and 4 ounces chopped semisweet chocolate together, stirring until smooth; cool slightly.
Whisk 1 cup granulated sugar into the melted chocolate mixture, then whisk in 2 large eggs one at a time and 1 teaspoon pure vanilla extract until combined.
Sift and add 1/3 cup unsweetened cocoa powder, 1/2 cup all purpose flour, and 1/4 teaspoon fine salt to the chocolate mixture; fold gently just until no streaks of flour remain.
Fold in optional 1/2 cup chopped peanuts or chocolate chips if using. Pour batter into the prepared pan, smoothing the top.
Bake 20 to 25 minutes, or until a toothpick inserted near the center comes out with a few moist crumbs but not wet batter. Cool completely in the pan on a wire rack.
While brownies cool, make the frosting: beat 1/2 cup softened unsalted butter with 1 cup creamy peanut butter until smooth and creamy.
Gradually add 2 to 2 1/2 cups sifted powdered sugar, beating on low until incorporated, then add 2 to 3 tablespoons whole milk or heavy cream as needed to reach spreadable consistency. Mix in 1 teaspoon pure vanilla extract and a pinch of fine salt, tasting and adjusting salt or sugar as desired.
Spread the peanut butter frosting evenly over the cooled brownies. For cleaner slices chill the frosted brownies 30 minutes to set the frosting.
Lift brownies from the pan using the parchment, slice into squares, and serve. Store leftovers covered at room temperature for 2 days or refrigerated for up to 5 days.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.