If baking right away, preheat oven to 350ºF. Line baking sheets with parchment paper.

In a medium bowl, whisk together the flour, baking soda, baking powder, cornstarch, and salt.

In the bowl of an electric mixer, beat the butter, cream cheese, granulated sugar, and brown sugar on medium-high speed until light and creamy, about 2 minutes. Add in the vanilla and the eggs, one at a time, beating well after each addition. Slowly beat in the flour mixture. Stir in the chocolate chips. 

If time permits: wrap dough in plastic wrap and refrigerate for at least 2 hours but no more than 72 hours. This allows the dough to “marinate” and for the final cookies to become softer, thicker, and more flavorful. Let dough sit at room temperature until it is just soft enough to scoop.

Using a medium (1 1/2-tablespoon size) spring-loaded scoop, drop balls of dough onto prepared baking sheets.

Bake for 10 to 11 minutes, or until barely golden brown. Don’t overbake - the cookies will continue to cook from residual heat. Cool for 5 minutes before removing to wire racks to cool completely. Cookies can be stored in an airtight container at room temperature for up to 3 days.