In a stand mixer, add the butter and cream cheese. Cream until mixed well and smooth. Add in sugars and cream again for 2-3 minutes. Add in vanilla and egg. Beat until mixed well (making sure to scrape down the bowl).
Add in flour, cornstarch, baking soda, and salt beat until combined well.
Stir in chocolate chips.
Refrigerate for 1 hour.
Preheat oven to 350F and line a cookie sheets with parchment paper.
Using a 2 tsp cookie scoop, scoop the dough and place on parchment paper, about 1 1/2 in to 2 in apart.
Bake for 7-8 minutes until lightly browned. (They may look undercooked but that is okay!)
Enjoy!