Ingredients:

  • 3/4 cup (170g) unsalted butter, softened
  • 3/4 cup (150g) packed light brown sugar
  • 1/4 cup (50g) granulated sugar
  • 1 large (50g) egg, room temperature
  • 2 tsp (10ml) pure vanilla extract
  • 2 1/4 cups (280g) all-purpose flour
  • 1 tsp (5g) cornstarch
  • 1/2 tsp (3g) baking soda
  • 1/2 tsp (3g) sea salt
  • 1 1/2 cups (255g) semi-sweet chocolate chips
  • 1/2 cup (60g) chopped walnuts
  • 1/2 tsp (3g) flaky sea salt

Instructions:

  1. Preheat oven to 350°F (175°C) and line a 13x18 inch rimmed baking sheet with parchment paper, leaving an overhang on the sides.
  2. In a large bowl, cream together softened butter, brown sugar, and granulated sugar with a spatula until smooth and pale. Stir in the egg and vanilla extract until glossy.
  3. Sift in flour, cornstarch, baking soda, and salt. Gently fold the mixture until no streaks of flour remain, then fold in chocolate chips and walnuts.
  4. Transfer dough to the prepared pan and press evenly into all four corners. Bake for 18–22 minutes until edges are deep golden brown and the center is slightly underbaked.
  5. Immediately sprinkle with flaky sea salt. Remove from oven and cool completely in the pan for at least 30 minutes before cutting.