In a mixing bowl, whisk together flour, cornstarch, baking powder, baking soda, and salt, then set aside.
2 ½ cups flour, 1 teaspoon cornstarch, ½ teaspoon baking powder, ¼ teaspoon baking soda, ½ teaspoon salt
In a separate mixing bowl, mix the sugars and butter until fluffy.
1 cup butter, ¾ cup light brown sugar, ¼ cup granulated sugar
After scraping the side of the mixing bowl, add the egg, egg yolk, and vanilla, then continue whisking for two minutes.
1 large egg, 1 egg yolk, 2 teaspoons vanilla extract
Gradually add the dry ingredients until fully mixed and smooth.
Fold in 1 cup of the chocolate chunks.
1 ½ cups chocolate chunks
Let the cookie dough sit in the refrigerator for 30 minutes.
Spoon out about a cup of cookie dough and form into a ball 2-3” in diameter
Cover a baking sheet with parchment paper and place the dough balls 2” apart. You can bake them as dough balls or form the dough into a flatter cookie shape.
Bake at 350º F for 15 minutes.
Let cookies rest on baking sheet for 10 minutes and then transfer to a backing rack.
flaky sea salt