Ingredients:

  • 1 cup (225g) unsalted butter, softened
  • 1 cup (200g) brown sugar, packed
  • 1/2 cup (100g) granulated sugar
  • 2 large eggs, room temperature
  • 2 tsp (10ml) vanilla extract
  • 3 cups (375g) all-purpose flour
  • 2 tsp (6g) cornstarch
  • 1 tsp (5g) baking soda
  • 3/4 tsp (4g) sea salt
  • 2 cups (340g) semi-sweet chocolate chips
  • 1/2 cup (115g) unsalted butter, softened
  • 2 cups (240g) powdered sugar
  • 1/4 cup (25g) cocoa powder, unsweetened
  • 2 tbsp (30ml) heavy cream
  • 1 tsp (5ml) vanilla extract

Instructions:

  1. Cream together the softened butter, brown sugar, and granulated sugar until the mixture is pale and fluffy (about 3 minutes). Beat in the eggs one at a time, followed by the vanilla extract, ensuring the emulsion is smooth.
  2. Whisk the flour, cornstarch, baking soda, and salt in a separate bowl. Gradually incorporate the dry ingredients into the wet mixture on low speed. Fold in 1 1/2 cups of chocolate chips by hand until just combined.
  3. Line a 12-inch springform or pizza pan with parchment paper. Press the dough evenly into the bottom using palms to flatten it toward the edges. Press the remaining 1/2 cup of chocolate chips firmly into the top surface.
  4. Bake at 350°F (175°C) for 18-22 minutes until the edges are a deep golden brown but the center still has a slight, soft jiggle.
  5. Allow the cake to cool completely in the pan to let the structure set. Whisk together the frosting ingredients (butter, powdered sugar, cocoa powder, heavy cream, and vanilla) and spread over the cooled cake.