Pre-heat your oven to 350° and prepare a baking sheet by lining it with parchment paper or a non-stick mat. (See notes about using a stand or hand mixer)
Add the softened butter, white sugar and brown sugar to a mixing bowl (or stand mixer) and beat for about 2 minutes. The mixture will get light and fluffy.
Add in the 2 eggs, and vanilla extract and beat again just until everything is fully combined.
In a separate bowl, whisk together the flour, cornstarch, and baking soda.
Add the flour mixture to the butter/sugar mixture in thirds. It will be VERY thick but it will come together with a little elbow grease! (I like to switch to a wooden spoon to do this)
Add in the chocolate chips and mix again.
Scoop out the dough into roughly the size of a golfball (about 2 tablespoons). Place them on the lined baking sheet.
Bake for 12-14 minutes just until the very edges start to turn a golden color.
Allow to cool on the baking sheet for 5-10 minutes.
Once completely cooled, store in an airtight container with a slice of bread to keep them soft for up to 5 days!
Notes
This recipe can easily be made in a stand mixer but I usually just make it with a hand mixer and spatula. The dough is very thick so just be aware that using a stand mixer will be easier but either way is fine!If you don't have cornstarch, you can still make these. The cornstarch just gives their wonderfully chewy texture!When you remove these from the oven, make sure to gently place the baking sheet down and not slam it. That can cause the cookies to flatten and not keep their shape.