In a medium bowl, combine all-purpose flour, baking soda, cornstarch, and fine sea salt. Whisk these dry ingredients together thoroughly until well blended and set aside.

In a large mixing bowl, beat together softened unsalted butter, granulated sugar, and light brown sugar using an electric mixer on medium speed for about 3-4 minutes until pale and fluffy.

Add eggs one at a time, mixing well after each addition, then mix in pure vanilla extract.

Gradually add the flour mixture to the wet ingredients, mixing on low speed until just combined, about 30 seconds.

Gently fold in semi-sweet chocolate chips with a spatula.

Cover the bowl with plastic wrap and refrigerate the dough for at least 1 hour.

Preheat your oven to 375°F (190°C) and line two baking sheets with parchment paper.

Portion out the dough into 1.5-tablespoon balls and place them 2 inches apart on the prepared baking sheets.

Bake the cookies for 10-12 minutes until the edges are golden brown, but the centers appear slightly underbaked.

Allow the cookies to cool on the baking sheet for about 5 minutes before transferring to a wire rack.