Ingredients:

  • 1 cup (240ml) unsalted butter, melted
  • 1 cup (200g) granulated sugar
  • 1 cup (220g) packed brown sugar
  • 4 large eggs
  • 1 teaspoon vanilla extract
  • 1 cup (130g) all-purpose flour
  • 1 cup (80g) unsweetened cocoa powder
  • ½ teaspoon salt
  • ½ teaspoon baking powder
  • 1 cup (250g) creamy peanut butter
  • ½ cup (60g) powdered sugar
  • 1 teaspoon vanilla extract

Instructions:

  1. Preheat your oven to 350°F (175°C). Grease or line the baking pan with parchment paper for easy removal.
  2. In a large mixing bowl, whisk together melted butter, granulated sugar, and brown sugar until smooth. Add eggs one at a time, mixing well after each addition. Stir in vanilla.
  3. In a separate bowl, sift together flour, cocoa powder, salt, and baking powder.
  4. Gradually add the dry mixture to the wet ingredients, folding gently with a spatula until just combined.
  5. In a small bowl, mix creamy peanut butter, powdered sugar, and vanilla until smooth.
  6. Pour about two-thirds of the brownie batter into the prepared pan, spreading evenly. Drop spoonfuls of the peanut butter mixture over the brownie base followed by the remaining brownie batter. Use a knife or skewer to swirl the peanut butter mixture into the brownie batter.
  7. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
  8. Allow the brownies to cool in the pan on a rack for about 15 minutes before slicing into squares.