Ingredients:

  • 1 cup unsalted butter, melted and cooled
  • 1 1/2 cups dark brown sugar, packed
  • 1/2 cup granulated white sugar
  • 2 large eggs, room temperature
  • 1 large egg yolk, room temperature
  • 1 tablespoon pure vanilla extract
  • 2 1/8 cups all-purpose flour
  • 1 teaspoon baking soda
  • 3/4 teaspoon fine sea salt
  • 2 cups semi-sweet chocolate chips
  • 1 pinch flaky sea salt for sprinkling

Instructions:

  1. Preheat your oven to 325°F and line a 9x13 metal pan with parchment paper, leaving an overhang for easy removal.
  2. Melt 1 cup unsalted butter in a small saucepan until just liquid, then transfer to a large bowl to cool. Wait until it is no longer hot to the touch.
  3. Whisk 1 1/2 cups dark brown sugar and 1/2 cup white sugar into the cooled butter. Mix until the grains look like wet sand.
  4. Add 2 eggs, 1 yolk, and 1 tablespoon vanilla extract. Whisk vigorously for 2 minutes until the mixture lightens in color.
  5. Fold in 2 1/8 cups flour, 1 teaspoon baking soda, and 3/4 teaspoon fine sea salt. Stop as soon as the last white streak disappears.
  6. Gently fold in 2 cups semi sweet chocolate chips.
  7. Spread the dough into the prepared pan using an offset spatula. Ensure the corners are filled evenly.
  8. Slide the pan onto the center rack. Bake for 25 minutes until the edges are a deep bronze and the center is puffed but set.
  9. Remove from the oven and immediately sprinkle with flaky sea salt. Hear the subtle sizzle as the salt hits the hot chocolate.
  10. Let the pan sit on a wire rack for at least 30 minutes. The residual heat finishes the center without drying out the edges.