Add butter, brown sugar, and sugar to a mixing bowl, beat until light and fluffy. (about 3-4 minutes.)
Continue beating and add in the eggs and vanilla until all ingredients are mixed well.
Add the flour, baking soda, salt, and chocolate chips in the mixing bowl. Mix well
Wrap the bowl with plastic wrap.
Put in the refrigerator for at least 30 minutes or up to 24 hours.
Before removing the chilled dough from the refrigerator, preheat the oven to 350 degrees.
Prep the Milk Shot Cookie Pan with nonstick baking spray.
Press the chilled cookie dough into the wells of the pan. Press the dough to fit the wells with the cup piece of the cookie pan.
(Make sure that the dough has made an indention in the center of the cup and up the sides of the well.
Bake at 350 degrees for 10-12 minutes or until they are a light golden brown.
Set aside the cookies while still in the pan for 20 minutes.
This will let the cookies become firm.
Use a knife to loosen the baked cups from the pan.
Transfer the cookies to a cooling rack to cool at room temperature.