Peanut Butter Frosted Brownies Recipe

I made the BEST Brownie smothered in peanut butter frosting, and my Easy Peanut Butter Frosting For Brownies turns it into the most decadent take-along dessert for parties, potlucks, family gatherings and tailgating this season!

I never thought a brownie could steal the show until I smothered the fudgiest slab of semisweet chocolate with silky creamy peanut butter. I tested so many combos, but the Easy Peanut Butter Frosting For Brownies actually holds up when you cut into it, and it somehow tastes like a memory you can’t place.

Bring these to a Brownie Bar Party and people will circle the table like it’s a magnet, asking who made them. They’re a little messy, sometimes crumbs get everywhere, and thats part of why I keep making them all season long.

Ingredients

• Unsalted butter: adds rich fat, helps texture, calories high, little nutrients
• Chocolate: deep cocoa flavor, gives fudgy chew, some antioxidants, lots of sugar
• Granulated sugar: pure sweetener, adds structure and shine, empty calories, quick energy
• Brown sugar: adds molasses warmth, keeps brownies moist, kinda chewier, sugary
• Eggs: binders, add lift and protein, nutrients like choline, adds richness
• Peanut butter: creamy protein and fat, adds savory sweet depth, calorie dense
• Cocoa powder: intense chocolate flavor, low fat, antioxidants, gives bitterness and depth
• Flour: provides structure, carbs for chew, little fiber unless whole grain

Ingredient Quantities

• 1 cup (2 sticks, 226g) unsalted butter, melted
• 8 oz (225g) semisweet or bittersweet chocolate, chopped or chocolate chips
• 1 1/2 cups (300g) granulated sugar
• 1/2 cup (100g) packed light brown sugar
• 4 large eggs
• 1 tablespoon vanilla extract
• 1 cup (125g) all purpose flour
• 1/2 cup (50g) unsweetened cocoa powder, sifted
• 1/2 teaspoon kosher salt
• 1/2 cup (1 stick, 113g) unsalted butter, softened (for frosting)
• 1 cup (250g) creamy peanut butter, room temp
• 2 to 3 cups (240-360g) powdered sugar, sifted
• 2 to 4 tablespoons milk or heavy cream, as needed
• 1 teaspoon vanilla extract (for frosting)
• Pinch kosher salt, optional (for frosting)
• Flaky sea salt or 1/2 cup chopped roasted peanuts for sprinkling, optional

How to Make this

1. Preheat oven to 350F (175C). Line a 9×13 inch pan with parchment leaving an overhang and lightly butter the parchment or pan so brownies release easy later.

2. Put 1 cup (2 sticks) unsalted butter and 8 oz chopped semisweet chocolate in a heatproof bowl and melt gently, either in 30 second bursts in the microwave stirring between each, or over a double boiler. Stir until smooth, let cool a few minutes so it’s warm not scalding.

3. Whisk the melted chocolate with 1 1/2 cups granulated sugar and 1/2 cup packed light brown sugar until glossy. Add the 4 large room temp eggs one at a time, whisking each in fully, then stir in 1 tablespoon vanilla extract. Don’t panic if it looks glossy and thick, thats right.

4. Sift together 1 cup all purpose flour, 1/2 cup unsweetened cocoa powder and 1/2 teaspoon kosher salt, then fold the dry mix into the chocolate mixture gently until just combined. Overmixing makes dry brownies so stop when there are no big streaks of flour.

5. Spread the batter evenly into the prepared pan, tapping the pan a couple times to level and pop big air bubbles. Bake 25 to 30 minutes until the edges are set and a toothpick inserted in the center comes out with a few moist crumbs but not raw batter. Oven temps vary, so start checking at 22 minutes.

6. Cool the brownies completely in the pan on a wire rack. Use the parchment overhang to lift the slab out once cool, this makes frosting easier and cleaner.

7. Make the frosting: beat 1/2 cup softened unsalted butter with 1 cup creamy peanut butter until smooth and fluffy. Add 1 teaspoon vanilla extract and a pinch of kosher salt if you like it a little savory. Sift in 2 cups powdered sugar and beat, then add 2 to 4 tablespoons milk or heavy cream as needed to get a spreadable consistency. If you want thicker frosting, add the third cup of powdered sugar. Taste and adjust salt or sweetness.

8. Spread the peanut butter frosting over the fully cooled brownies with an offset spatula or back of a spoon. Smooth it quick, you can chill 15 to 30 minutes after spreading so it firms up for cleaner cutting.

9. Sprinkle flaky sea salt or 1/2 cup chopped roasted peanuts on top if desired, press lightly so they stick. For clean squares, run a sharp knife under hot water, wipe dry and slice, repeating the warm wipe between cuts. Store airtight at room temp up to 3 days or refrigerate up to a week.

Equipment Needed

1. 9×13 inch baking pan (lined with parchment, leave an overhang)
2. Parchment paper and a bit of butter or nonstick spray to grease
3. Heatproof bowl (microwave safe) and a small saucepan for a double boiler option
4. Whisk
5. Measuring cups and spoons
6. Fine-mesh sieve or sifter for the flour and cocoa
7. Rubber spatula for folding and scraping
8. Offset spatula or the back of a spoon for spreading frosting
9. Wire cooling rack and a sharp knife for warm-wipe slicing

FAQ

Peanut Butter Frosted Brownies Recipe Substitutions and Variations

• Unsalted butter (melted) → Neutral oil (canola, vegetable, grapeseed): use 3/4 cup oil for 1 cup butter by volume. Brownies stay fudgy but lose a little buttery flavor, so toss in a pinch of flaky salt if you want more depth.
• 8 oz semisweet chocolate → 8 oz chocolate chips or chopped bittersweet/milk chocolate by weight: swap 1:1. If you go milk chocolate, cut the granulated sugar by about 2 to 3 tablespoons so it doesn’t get too sweet.
• 1 cup all purpose flour → 1 cup (by weight 125g) gluten free 1:1 baking blend or whole wheat pastry flour (use same weight): expect a slightly different crumb, weigh the flour for best results instead of scooping.
• 1 cup creamy peanut butter → natural peanut butter (stirred) or other nut butter (almond, cashew) 1:1: stir natural peanut butter well before measuring, and if frosting gets too thin add more sifted powdered sugar a little at a time.

Pro Tips

1) Watch the chocolate temp and temper the eggs. Let the melted chocolate cool until just warm to the touch, dont add scalding chocolate to cold eggs or theyll start to cook. If youre nervous, whisk an egg in a small bowl and add a spoonful of chocolate to it first, then mix that back into the batter.

2) Keep these brownies fudgy by underbaking a little and checking early. Ovens lie, so stick an oven thermometer in if you can and start testing at 22 minutes. Pull them when there are still a few moist crumbs on the tester, not a dry toothpick.

3) Make the frosting silky and not grainy. Beat the peanut butter with the softened butter until fluffy, sift the powdered sugar, then add milk 1 tablespoon at a time until spreadable. If your peanut butter is stiff, microwave it 6 to 10 seconds to loosen it, then mix — dont overdo the heat.

4) For clean, tidy squares and nice toppings. Chill the frosted slab 15 to 30 minutes so the icing firms, then use a very sharp knife warmed under hot water and wiped dry between cuts for perfect edges. Press flaky sea salt or chopped peanuts gently so they stick and wont fall off when you cut.