Eating peanut butter straight from the jar with a spoon at nine on a random Tuesday night is exactly what led to these peanut butter brownies. A socially acceptable way to consume that much peanut butter felt necessary, and stuffing it inside fudgy chocolate batter turned out to be the answer.
A first attempt at this peanut butter brownie recipe once ended with chocolate batter somehow reaching the ceiling, but the resulting squares tasted good enough to justify the mess. Stuffing a thick layer of peanut butter dough inside rich brownie batter counts as one of the better decisions made in a kitchen this year. Here is exactly how I do it.
Why You’ll Love This Recipe
- Deceptively fast. These look like they took all day, but they only take about 15 minutes of active effort in the kitchen.
- Crowd-pleasing power. Bringing these to a potluck guarantees a fight over the corner pieces.
- Zero precision required. The oven hides every messy layer, so perfection was never the goal.
- Kid-approved. Children treat a hidden peanut butter cup inside a brownie like actual wizardry.
Tools You’ll Need
Nothing fancy, I promise.
- 9-inch square baking pan This size gets the thickness right, though an 8-inch pan works with a slightly longer bake time.
- Mixing bowls. A couple of microwave-safe ones handle the chocolate step easily.
- Electric mixer. Handheld or stand, either one beats the peanut butter filling into submission.
Ingredients
Brownie Batter
- 1/2 cup salted butter – Yes, salted. We need the salt to cut the sweetness, trust me.
- 8 ounces coarsely chopped semi-sweet chocolate – Do not use chocolate chips here, they have stabilizers that make them melt weirdly. Buy real baking chocolate bars.
- 3/4 cup granulated sugar – For the classic crinkly top.
- 1/4 cup packed light brown sugar – This is what makes the base so chewy.
- 3 large eggs – Room temperature if you can remember, but I usually forget and just soak them in warm water for five minutes.
- 1 teaspoon pure vanilla extract – The good stuff if you have it.
- 1/2 cup + 2 Tablespoons all-purpose flour – Spoon and level it so you do not end up with dry chocolate peanut butter brownies.
- 2 Tablespoons unsweetened cocoa powder – For that extra deep chocolate punch.
- 1/4 teaspoon salt – A little extra insurance against a sugar coma.
Peanut Butter Filling
- 3/4 cup creamy peanut butter – Use the standard processed kind. Natural peanut butter will turn this into an oily disaster.
- 1 cup confectioners’ sugar – This thickens the filling so it acts like a dough.
- 2 teaspoons pure vanilla extract – Because vanilla makes everything better.
- 2 Tablespoons milk – Just enough to bring the dough together.
- 2 Tablespoons each chocolate chips and peanut butter chips – For sprinkling on top, because we have zero chill.
How To Make Peanut Butter Brownies
Set your expectations to “messy but worth it,” because stuffing these is a beautifully chaotic process.
- Melt the base: Melt the butter and chocolate together until smooth. If you use the microwave, do it in 20-second bursts so you do not scorch the chocolate—burnt chocolate smells like sadness and failure. Let it cool for 10 minutes.
- Make the filling: Beat the peanut butter, powdered sugar, vanilla, and milk until it looks like crumbly cookie dough. If it looks a little dry, that is exactly what you want for brownies with peanut butter inside.
- Prep the pan: Line your pan with foil, leaving an overhang. This is your “sling” to pull them out later, unless you enjoy digging brownies out with a butter knife and ruining the first row.
- Mix the batter: Whisk the sugars into the cooled chocolate, then add the eggs one at a time, followed by vanilla. Gently fold in the flour, cocoa, and salt. Do not overmix, or your arms will get tired and the brownies will get tough.
- Assemble the layers: Spread half the batter in the pan. Flatten chunks of the peanut butter filling and lay them on top. It does not need to look pretty; nobody will see the inside until they bite into it. Spread the rest of the batter over the top and press in your chips.
- Bake it up: Bake at 350°F for 35-36 minutes. The center might crack a little because the air from the peanut butter layer is escaping—this is totally fine and honestly makes them look more rustic.
- Cool and cut: Let them cool completely before cutting. I know waiting is physical torture, but if you cut them hot, you will end up with a delicious puddle instead of squares.
♥ The Misfit Tips!
- Respect the cooling test. Cutting these while still warm once dragged the filling everywhere and left a mess resembling a crime scene. A full cool-down, or an hour in the fridge, produces clean slices.
- Try the lazy swirl shortcut. Thinning the filling with extra milk and swirling it through the batter with a butter knife turns this into peanut butter swirl brownies instead of a stuffed version.
- Prep the dough ahead. Making the peanut butter dough a day ahead and storing it in the fridge simplifies the whole process for anyone prone to feeling overwhelmed by multi-step recipes.
Make it yours
- Espresso version. Stirring a teaspoon of instant espresso powder into the chocolate batter deepens the flavor against the sweet peanut filling.
- Pretzel crunch version. Pressing crushed pretzels into the top layer before baking adds a salty crunch to every bite.
Perfect Pairings
These peanut butter brownies suit two specific pairings particularly well.
- A massive glass of ice-cold milk – obviously.
- A scoop of vanilla bean ice cream melting aggressively over a warm square.
- Your next neighborhood block party, where you will secure your status as the favorite neighbor.
- A strong cup of black coffee to balance out the intense sweetness.
How to Store Peanut Butter Brownies
❤
- Fridge. Up to a week in an airtight container, and the chilled texture turns incredibly fudgy, almost like a dense truffle.
- Freezer. Up to three months wrapped tightly in plastic wrap, thawed overnight in the fridge.
- Reheat. Fifteen seconds in the microwave brings back that gooey, fresh-from-the-oven texture.
- Storage note. The chips on top may pick up a little condensation in the fridge, though nobody complains about slightly sweaty chocolate when the flavor holds up this well.
Peanut Butter Brownies
These peanut butter brownies prove that stuffing a thick peanut fudge layer inside rich chocolate batter beats a plain pan every time. This peanut butter brownie recipe delivers real baking chocolate, a stable peanut butter filling, and a fudgy texture that rivals anything from a bakery case. Whether stuffed thick in the center or swirled through as peanut butter swirl brownies, this batch of chocolate peanut butter brownies disappears fast at any gathering.
Ingredients
Equipment
Method
- Melt the butter and chopped chocolate in a medium saucepan on medium heat, stirring constantly, about 5 minutes. Or melt in a medium microwave safe bowl in 20 second increments, stirring after each, in the microwave. Remove from the heat, pour into a large mixing bowl, and allow to slightly cool for 10 minutes.
- While the chocolate mixture is cooling, make the peanut butter filling. In a medium bowl using a handheld or stand mixer fitted with a paddle attachment, beat the peanut butter, confectioners’ sugar, vanilla, and milk together on medium-high speed until combined. The mixture will be very thick—like a crumbly cookie dough. Set aside.
- Adjust the oven rack to the lower third position and preheat oven to 350°F (177°C). Line the bottom and sides of a 9-inch square baking pan with aluminum foil, leaving an overhang on all sides. Set aside.
- Whisk the granulated and brown sugars into the cooled chocolate/butter mixture. Add the eggs, one at a time, whisking until smooth after each addition. Whisk in the vanilla. Gently fold in the flour, cocoa powder, and salt.
- Pour/spread half of the brownie batter into the prepared baking pan. Take large chunks of the peanut butter filling and flatten with your hands. Place flat pieces in an even layer on top of the brownie layer, as shown in the photo above. Pour/spread the remaining brownie batter on top. Top with the chocolate chips and peanut butter chips. Using the back of a spatula, gently press the chips into the brownie batter.
- Bake for 35-36 minutes or until the brownies begin to pull away from the edges of the pan. (The brownies may slightly crack in the center—that’s because air in between the peanut butter layers is trying to escape. That’s normal!) A toothpick inserted in the center should come out with only a few moist crumbs when the brownies are done. All ovens are different, so keep an eye on them after 30 minutes and use the toothpick test to see when yours are finished.
- Allow the brownies to cool completely in the pan set on a wire rack. Once cooled, lift the foil out of the pan using the overhang on the sides and cut into squares. For neat squares, I use a very sharp knife and wipe it clean with a paper towel after each cut.