Ingredients:

  • 1/2 cup (113g) unsalted butter, melted, plus more for greasing the pan
  • 1 cup (200g) granulated sugar
  • 1/2 cup (100g) packed light brown sugar
  • 2 large eggs
  • 1 teaspoon vanilla extract
  • 1/2 cup (60g) all-purpose flour
  • 1/2 cup (50g) unsweetened cocoa powder
  • 1/4 teaspoon baking powder
  • 1/4 teaspoon salt
  • 1/2 cup (85g) semi-sweet chocolate chips
  • 2 medium ripe bananas (about 1 cup mashed)
  • 1/4 cup (57g) unsalted butter, melted
  • 1/4 cup (50g) granulated sugar
  • 1 large egg yolk
  • 1 teaspoon vanilla extract
  • 1/2 cup (60g) all-purpose flour
  • 1/4 teaspoon ground cinnamon
  • 1/4 teaspoon ground nutmeg
  • Pinch of salt

Instructions:

  1. Preheat oven to 350°F (175°C). Grease and line an 8x8 inch baking pan with parchment paper, leaving an overhang.
  2. Whisk together melted butter and sugars for the brownie base. Beat in the egg and vanilla until smooth.
  3. In a separate bowl, whisk together flour, cocoa powder, baking powder, and salt.
  4. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Fold in chocolate chips.
  5. Mash the bananas in a medium bowl. Add the melted butter, sugar, egg yolk, and vanilla extract and whisk to combine for banana bread swirl.
  6. Add the flour, cinnamon, nutmeg, and salt to the banana mixture. Stir until just combined.
  7. Pour the brownie batter into the prepared pan. Dollop spoonfuls of the banana bread batter over the brownie batter.
  8. Use a knife or skewer to gently swirl the banana bread batter into the brownie batter. Don't overmix!
  9. Bake for 30-35 minutes, or until a toothpick inserted into the center comes out with moist crumbs attached.
  10. Let cool completely in the pan before lifting out using the parchment paper overhang. Cut into squares and serve.