Brown the butter, then allow to solidify to soft butter.
Cream the butter and sugars together. Be sure to do this for 1-2 minutes so it is quite fluffy.
Mix in the egg and egg yolks. Then add the vanilla.
In a separate bowl combine the flour, cornstarch, salt, baking soda, and baking powder.
Add the dry ingredients to the wet and mix until just combined.
Fold in the chocolate chips.
Using a spoon or cookie scoop form balls, and place on a cookie sheet that has been lined with a silicone mat or parchment paper. Slightly flatten the dough balls.
Place cookie sheet in the fridge for one hour.
While the cookies are chilling preheat the oven to 350°.
After the hour is up, take the transfer the cookies, 8-12 at a time to a new cookie sheet, also lined with parchment paper or a silicone mat. Be sure to keep the cookies you are not currently baking in the fridge.
Bake the cookies for 12-14 minutes. They should be just starting to brown on the edge. The center may still look a little undone.
After baking take the sheet out of the oven, and allow cookies to rest on tray for 10 minutes before removing to a cooling rack.
