
Preheat oven to 400 degrees. Cream butter, brown sugar, and granulated sugar for 4 minutes until light and fluffy.
Add eggs and vanilla, mixing for 1 minute longer.
Stir in flour, cornstarch, baking soda, and salt until combined. Fold in chocolate chips.
Chill dough for 24 hours if possible, or proceed to scoop onto baking sheets.
Bake for 8-11 minutes until edges turn light golden. Let set for 5 minutes before removing.