Preheat the oven to 350°F and line a large jelly roll pan with parchment paper and spray with nonstick cooking spray. Set aside. In a medium bowl, whisk together the flour, cornstarch, baking soda, and salt. Set aside.
Add the flour mixture to the butter mixture and mix just until combined. Mix in the chocolate chips. Spread the cookie dough out on the parchment-lined jelly roll pan and use your hands or a rubber spatula to spread the dough all the way to the edges. It might seem like there isn't enough dough, but trust me, there is.