Decadent Chocolate Peanut Butter Brownies Recipe

These chocolate peanut butter brownies are ultra-fudgy chocolate brownies swirled with creamy peanut butter, then finished with extra Reese’s cups and mini chocolate chips. If you love the chocolate-and-peanut-butter pairing, this is the recipe for you.

Happy first recipe of the year! There’s no better way to start than with the classic and irresistible combination of chocolate and peanut butter. These decadent brownies are rich and intensely fudgy — exactly what makes them so satisfying.

The batter uses two kinds of cocoa powder plus melted chocolate chips for extra depth and fudginess. Creamy peanut butter is spooned across the top and swirled into the batter before baking, giving perfect pockets of peanut butter throughout.

Why this recipe works

• Ultra-fudgy texture – The combination of melted chocolate, chocolate chips and two cocoa powders creates a thick, fudgy brownie with a desirable crinkle top.
• Simple method – No electric mixer needed. Everything comes together in a single bowl for easy prep and minimal cleanup.
• Balanced peanut butter swirls – Dollops of creamy peanut butter are swirled into the surface so every square has the ideal chocolate-to-peanut-butter ratio.

Ingredient notes

The full ingredient list is in the recipe card below. These notes highlight key components and substitutions.

Butter – Use unsalted butter, melted.

Sugar – White granulated sugar helps produce the glossy crinkle top typical of fudgy brownies.

Cocoa powders – Using both unsweetened and dark cocoa gives the brownies a deeper chocolate flavor. If needed, you can use only one type, but the texture and flavor will vary slightly.

Peanut butter – Use creamy peanut butter for smooth, easy-to-swirl ribbons.

Chocolate chips – Dark or semi-sweet chocolate chips are recommended for melting into the batter and balancing the sugar. Mini chocolate chips sprinkled on top add small bursts of chocolate and texture; avoid milk chocolate if you want to keep the sweetness from overpowering the brownies.

Step by step instructions

Follow these steps to make the Chocolate Peanut Butter Brownies. You’ll need an 8×8 (or 9×9) square pan lined with parchment paper for easy removal, a large mixing bowl, a whisk and a spatula.

Step 1 – Prep. Preheat the oven to 350°F. Line an 8×8 (or 9×9) pan with parchment paper on the bottom and two sides, and grease the remaining sides.

Step 2 – Melt butter and chocolate. Melt the butter, transfer it to a large bowl while hot, then add the chocolate chips and white sugar. Whisk until combined; the mixture will look thick and slightly grainy — that’s normal.

Step 3 – Add eggs and vanilla. Whisk in the eggs one at a time, then whisk in the vanilla. The mixture should become glossy and smooth.

Step 4 – Fold in dry ingredients. Gently fold in the flour, both cocoa powders, baking powder and salt using a spatula. Avoid overmixing to keep the brownies dense and fudgy.

Step 5 – Pour and swirl. Spread the batter evenly into the prepared pan. Drop dollops of creamy peanut butter across the surface and swirl them into the batter with a butter knife or small spatula for attractive ribbons of peanut butter.

Step 6 – Bake. Bake for 40–50 minutes. The edges should be set while the center still jiggles slightly; a toothpick inserted into the center should come out with moist crumbs but not raw batter. The brownies will continue to set as they cool. Allow them to cool completely in the pan before removing and cutting. Top with mini chocolate chips and chopped Reese’s peanut butter cups if desired.

Expert baking tips

• Measure flour correctly: spoon the flour into the measuring cup and level it off rather than scooping directly, which compacts the flour and can make brownies cakey. A kitchen scale is best.
• Add eggs one at a time to incorporate more air for a glossy, slightly lifted texture.
• Fold dry ingredients gently with a spatula after adding the eggs to preserve the fudgy crumb.
• Line the bottom and two sides of the pan with parchment and grease the other two sides to make removal and slicing easier.
• If the center is too underbaked, return the pan to the oven for an additional 5–10 minutes and recheck.

FAQ

Can I use only one type of cocoa powder? Yes. The recipe calls for two types to deepen the chocolate flavor, but using one type will still work. Keep the total cocoa measurement the same.

How do I know the brownies are done? The edges should be set while the center still jiggles slightly. A toothpick should pull out with moist crumbs (not raw batter). If it comes out wet with batter, bake a few minutes longer.

Why did my brownies sink? Sinking usually means they were underbaked in the middle. Even if the edges look set, ensure the center is somewhat set and tests with a toothpick.

Why didn’t my brownies get a crinkle top? The crinkle top depends on properly dissolving the sugar into the butter-chocolate mixture and avoiding over-beating after adding dry ingredients. Accurate measurements also help.

Can I reduce the sugar? This recipe relies on a higher sugar amount to create the crinkle top and fudgy texture. Reducing sugar will change the texture and finish; if you’re concerned about sweetness, use dark chocolate chips and skip extra toppings.

Recipe card