Preheat the oven to 400 degrees F (or 385 degrees F if your oven runs hot).

In a large mixing bowl, cream together the cold butter, brown sugar, and sugar for about 4 minutes until light and fluffy.

Add in the eggs and vanilla, mixing for an additional minute.

Stir in the flour, cornstarch, baking soda, and salt until combined.

Fold in the chocolate chips until evenly distributed.

If time allows, wrap dough tightly in plastic wrap and refrigerate for 24 hours to deepen flavors.

If short on time, scoop cookie dough onto baking sheet lined with parchment paper.

Bake cookies for 8-11 minutes, until the edges are light golden brown.

Let cookies sit on the baking sheet for 5 minutes before transferring them to a wire rack.