Combine the dry ingredients (flour, corn starch, baking soda, baking powder, salt) in a medium bowl.
In a larger bowl, whisk the butters and sugars together. Once creamy, add the eggs with vanilla and mix well.
Gradually add in the dry flour mixture.
Stir in the chocolate chips, keeping a handful on the side.
Cover tightly with plastic wrap and refrigerate for 1 hour minimum, or up to 72 hours.
When you are ready to bake, pre-heat oven to 350 degrees.
Roll 2 tbsp of cookie dough into a ball and line up onto baking sheet, with 2 inches between each cookie. Press 1-2 chips on top of the cookie.
Bake for 8-9 minutes and remove from oven promptly- you may notice gooey centers. Leave the cookies on the pan for 5 more minutes, and then allow them to cool on a cookie rack after 5 minutes. They will be perfectly soft and chewy. Enjoy with ice cream or milk!