Ingredients:

  • 1/2 cup unsalted butter, melted (115g)
  • 1 cup granulated sugar (200g)
  • 2 large eggs, room temperature
  • 1 tbsp vanilla extract
  • 1/2 cup Dutch-processed cocoa powder (45g)
  • 1/2 cup all-purpose flour (65g)
  • 1/4 tsp sea salt
  • 1 tsp espresso powder
  • 1 cup high-quality semi-sweet chocolate chips (170g)
  • 1 1/2 cups heavy whipping cream, divided (360ml)
  • 2 tbsp powdered sugar

Instructions:

  1. Preheat oven to 350°F (175°C). Line an 8x8 inch square baking pan with parchment paper, leaving an overhang on two sides for easy removal.
  2. In a medium bowl, whisk the melted butter and granulated sugar. Add the eggs and vanilla extract, beating vigorously until the mixture is pale and well-combined.
  3. Gently fold in the cocoa powder, flour, salt, and espresso powder until just combined. Avoid overmixing to maintain the fudgy texture.
  4. Spread the batter evenly into the prepared pan. Bake for 22–25 minutes, or until a toothpick inserted comes out with a few moist crumbs.
  5. Remove brownies from the oven and allow to cool to room temperature, then chill slightly in the refrigerator to create a stable base for the mousse.
  6. Heat 1/2 cup of the heavy cream until simmering. Place chocolate chips in a heat-proof bowl and pour the hot cream over them. Let sit for 5 minutes, then whisk until smooth to create a ganache.
  7. In a separate bowl, whip the remaining 1 cup of heavy cream with powdered sugar until stiff peaks form. Gently fold the cooled ganache into the whipped cream.
  8. Spread the chocolate mousse evenly over the chilled brownie base. Refrigerate for at least 2 hours before slicing into 16 squares.