- 2 1/4 cups all-purpose flour
- 1 teaspoon baking soda
- 1 1/2 teaspoons cornstarch
- 1/2 teaspoon salt
- 3/4 cup (1 1/2 sticks) unsalted butter, melted and cooled slightly
- 1 cup packed brown sugar
- 1/4 cup granulated sugar
- 1 large egg plus 1 large egg yolk, room temperature
- 2 teaspoons vanilla
- 1 cup semisweet chocolate chips, plus more for topping
- Sea salt, for sprinkling (optional)
- Heat oven to 350 degrees F. Line 9-inch round cake pan (or square pan) with foil.
- In large bowl, whisk flour, baking soda, cornstarch and salt until combined. In separate medium bowl, whisk butter, brown sugar, granulated sugar, egg, egg yolk and vanilla until combined. Add wet ingredients to dry ingredients. Using wooden spoon, stir ingredients until soft but thick dough forms. Stir in chocolate chips (you might need to use your hands to “knead” the chips into the dough).
- Press dough evenly into prepared pan. Press a few more chocolate chips into top of dough, if desired (this is purely for looks). Sprinkle lightly with sea salt, if desired. Bake 35-38 minutes until edges are golden brown. Cool completely in pan on cooling rack, about 1 hour. Remove cookie from pan using foil. Cut into bars or wedges. Store tightly covered at room temperature for up to 5 days.