Weigh or measure into a bowl the light brown and white sugars and set aside. In another bowl weigh or measure the flour, cornstarch, baking soda, salt, and run a whisk through to blend.
Add the butter and the sugars into a mixer bowl and cream them till light and fluffy. Add 1 egg at a time along with the vanilla extract. Blend for 2 minutes then scrape down the sides of the bowl and mix for another minute.
Turn the mixer to low and slowly add the flour mixture and mix till incorporated. Add the semi-sweet and the milk chocolate chips along with the glazed pecans.
Take a medium cookie scoop and add twelve scoops to a sheet pan. Bake at 350° for 12-14 minutes. Move the cookies to a cooling rack after cookies have baked.