Ingredients:

  • 113g unsalted butter, softened
  • 150g packed light brown sugar
  • 50g granulated cane sugar
  • 1 large egg
  • 5ml pure vanilla extract
  • 190g all-purpose flour
  • 30g unsweetened Dutch-process cocoa powder
  • 5g baking soda
  • 3g kosher salt
  • 255g dark chocolate chunks (70% cacao)

Instructions:

  1. Preheat the oven to 350°F (175°C) and line a 9x13 inch baking pan with parchment paper, leaving an overhang on the sides.
  2. In a large bowl, beat the softened butter, brown sugar, and cane sugar until the mixture is pale and fluffy.
  3. Add the egg and vanilla extract, beating on medium speed until the batter is smooth and well-emulsified.
  4. Sift in the flour, cocoa powder, baking soda, and salt.
  5. Stir with a rubber spatula until just combined, ensuring no streaks of flour remain.
  6. Fold in the dark chocolate chunks.
  7. Transfer the dough to the prepared pan and press into an even layer using your palms or a spatula.
  8. Bake for 22–25 minutes.