Combine butter and sugars in a large mixing bowl and use an electric mixer to beat until light and well-creamed.
Add eggs and vanilla extract and stir well.
In a separate mixing bowl, whisk together flour, cornstarch, baking powder, baking soda, and salt.
Gradually add dry ingredients to wet, stirring until completely combined.
Add chocolate chips and use a spatula to fold in until well distributed.
Cover bowl and chill for 30 minutes.
Meanwhile, line a baking sheet with parchment paper and preheat oven to 375F (190C).
Once dough has chilled, uncover and scoop into ⅓-cup sized scoops.
Drop onto prepared baking sheet, spacing at least 2” apart, and bake for 13-14 minutes, until edges are just beginning to turn light golden brown.
Allow cookies to cool before removing from the baking sheet.