Preheat the oven to 400 degrees. Line a baking sheet or two with parchment paper.
Cut your butter into slices. Add the butter slices into a large bowl (or stand mixer) with the sugars, and mix for a couple minutes until smooth. Scrape the bottom and sides of the bowl as needed. 1 cup butter, 3/4 cup brown sugar, 1/2 cup white sugar
Add in the eggs and vanilla extract and mix until combined. 2 large eggs, 1 tsp vanilla extract
Dump in the flour, cornstarch, baking soda, baking powder, and salt. Mix on low speed until the wet and dry ingredients combine into a soft dough. 2 3/4 cups all purpose flour, 1 TBS cornstarch, 1 tsp baking soda, 1 tsp baking powder, 1/2 tsp salt
Add in the chocolate chips and fold them into the dough until they are evenly mixed throughout. 3 cups chocolate chips
Measure out the batter to be 3 oz, grabbing and placing the dough with your hands. Don't pack it or roll the dough into a tight ball. Place 5 to 6 cookies per cookie sheet.
Bake in the preheated oven for 8-10 minutes, or until the cookie top and bottom are golden. The tops won't look done.
Remove from the oven and let the cookies rest on the baking pan for about 10 minutes. Transfer to a cooling rack to continue cooling completely, or for another 10 minutes to enjoy warm.