Preheat the oven to 350 degrees.
Cream the butter and sugars together in a stand mixer.
Add the egg and vanilla and cream them together.
In a separate bowl, measure 2 cups of flour (240g) and add cornstarch, baking soda, and salt.
Add the dry ingredients to the wet and mix to combine.
Pour in the bag of chocolate chips and mix well.
Using a medium sized cookie scoop or a 1/8 measuring cup, place balls of dough on a baking sheet.
Cook for 10-11 minutes or until edges just slightly begin to turn golden brown, then remove from oven and place pan on a cooling rack for at least 5 minutes. Allow to cool completely.
If freezing, place on a pan in the freezer and flash freeze for a few hours, then place in a container for long term storage.