Peanut Butter Swirled Brownies

From by Sarah Grossett
Peanut Butter Swirled Brownies

Peanut Butter Swirled Brownies Photo

Now here’s something I’ve wanted to do forever. I keep meaning to make brownies with a peanut butter swirl on top, but I just hadn’t gotten around to it yet. There’s always so many other peanut butter recipes I want to try.

I finally made a version of peanut butter swirl brownies, and they could not be easier or more delicious.

What makes these more impressive than other peanut butter swirl brownie recipes you’ve probably seen before is that these brownies have TWO layers of peanut butter swirl.

Peanut Butter Swirled Brownies Picture

It’s not just a swirl on top, but there’s also a hefty layer of peanut butter filling in the middle of the brownies too. So proud of that decision. A simple idea, but a good one, nonetheless. Typically, swirl brownies are just the top layer, but I strongly felt that one layer of peanut butter wasn’t going to be enough peanut butter for me.

The brownies are doctored-up box mix brownies. Someday I’m going to master a from-scratch brownie recipe, but that day has not arrived yet. In the meantime, box mix brownies work perfectly. With a little bit of help, they are fudgy and delicious.

The filling and topping are just butter, powdered sugar, vanilla, and of course, peanut butter. It’s like the homemade version of the filling of Reese’s peanut butter cups. Or Buckeyes. Perfectly sweet and buttery, and full of peanut butter flavor.

Peanut Butter Swirled Brownies Image

Each layer of peanut butter swirl is also sprinkled with Reese’s Pieces for a little color, crunch, and more peanut butter flavor, of course!

Did I mention how thick these brownies are? They are mile high! Almost twice as thick as a regular brownie. The baking time is much longer, but these brownies are totally worth the wait!

File 1 Peanut Butter Swirled Brownies

These pretty brownies are so simple to make, and feature a classic favorite pairing of chocolate and peanut butter. With layers of fudgy, rich brownie, and layers of sweetened peanut butter, these are sure to be a crowd-pleaser! 

Peanut Butter Swirled Brownies Pic


Peanut Butter Swirled Brownies Recipe



  • 1 box brownie mix
  • 1/4 cup water
  • 1/2 cup oil
  • 1 egg
  • 4 tablespoons unsalted butter, melted
  • 1/2 cup powdered sugar
  • 1 cup creamy peanut butter
  • 1 teaspoon pure vanilla extract
  • 1 cup reese's pieces, divided


  1. Preheat oven to 325°F.
  2. In a large bowl, combine brownie mix, water, oil, and egg.
  3. Spread half of the brownie batter into a greased 8x8-inch pan.
  4. In a medium bowl, combine butter, powdered sugar, peanut butter, and vanilla, stirring until smooth.
  5. Drop half of the peanut butter filling by tablespoonful onto the brownie batter in the pan. Using a knife, lightly swirl the peanut butter filling.
  6. Sprinkle with half of the Reese's pieces.
  7. Spread the remaining brownie batter into the pan.
  8. Drop the remaining peanut butter filling by tablespoonful onto the brownie batter. Using a knife, lightly swirl it.
  9. Sprinkle with remaining Reese's pieces.
  10. Bake for 50-55 minutes, or until a knife inserted near the center comes out clean.
  11. Remove to a wire rack to cool completely.
  12. Cut into bars, and enjoy!


  • The peanut butter filling thickens very quickly as the melted butter sets. If it’s too thick to drop by spoonful and easily swirl, you can pop it in the microwave for 5-10 seconds to thin it out.