Preheat your oven to 350 F. Line a baking sheet with parchment paper.
Cream the softened butter, brown sugar, and granulated sugar together until creamy and fluffy.
Add eggs one at a time and mix until smooth. Stir in vanilla.
In a separate bowl, whisk flour, baking soda, baking powder, salt, and cornstarch if using.
Add the dry ingredients to the wet mixture and fold gently. Do not overmix.
Stir in the chocolate chips. The dough should be thick.
Scoop dough onto the baking sheet using a cookie scoop. Space them out so they do not spread into each other.
Bake for 10 to 12 minutes, or until the edges are lightly golden and the centers look slightly soft.
Let the cookies cool for 5 minutes before transferring to a rack.
Enjoy warm. These cookies are at peak deliciousness when the chocolate is still melty.