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Close up of fluffernutter brownie.

Fluffernutter Brownies

Bring a childhood favorite back in the form of rich, decadent brownies. These Fluffernutter Brownies are swirled with peanut butter and sweet marshmallow fluff to make the ultimate dessert.
Course Dessert
Cuisine American
Keyword fluffernutter brownies
Prep Time 15 minutes
Cook Time 30 minutes
Total Time 45 minutes
Servings 12 servings
Author Meghan Payne-Hensley


  • 3/4 cup butter
  • 3/4 cup cocoa powder
  • 2 cups granulated sugar
  • 4 large eggs
  • 1 teaspoon vanilla extract
  • 1 1/2 cups all-purpose flour
  • 1 teaspoon kosher salt
  • 7.6 ounce bag unwrapped mini reese's peanut butter cups
  • 1/4 cup peanut butter
  • 1/4 cup marshmallow fluff


  • Preheat oven to 350 degrees F. Grease a 9x9 baking pan. Set aside.
  • Heat a large dutch oven or pot over medium heat. Add butter and allow to melt. Whisk in cocoa powder then remove from heat. Stir in sugar. Add eggs and vanilla extract. Whisk until smooth. Stir in flour and salt until you no longer see any flour. Gently fold in peanut butter cups. Spread batter into prepared pan.
  • Place peanut butter in a microwave safe dish. Place marshmallow fluff in another microwave safe bowl. Place in microwave and cook for 20 seconds. Drop dollops of each all over the brownie batter. Swirl with a knife or toothpick. Bake for 25 to 30 minutes, until no longer gooey in the center.