Preheat the oven to 350F.
Line cookie sheets with parchment paper or silicone baking mats.
In a medium bowl stir together the melted butter and sugars.
Stir in the egg and vanilla until evenly mixed. (Make sure the butter isn't still warm before adding in the egg)
In a medium bowl whisk together the flour, cornstarch, baking soda and salt.
Stir the flour mixture into the butter mixture.
Fold in 1/2 cup chocolate chips.
Form into balls about 1 -1.5 tsp in size and place 1 inch apart on the lined cookie sheets.
Bake for 5-6 minutes or until tops look just set. Start checking around 4 minutes to ensure they don't burn.
As the cookies cool, place a few extra chocolate chips on the top of each cookie using the reserved 1/4 cup of chocolate chips.