Preheat oven to 350°F.
In a stand mixer, cream butter and sugars until smooth. Add egg and vanilla, and mix until creamy.
In a separate bowl, whisk the dry ingredients together. Fold into the creamy mixture by hand. Do not over mix.
Fold in the chopped chocolate chips (you do not want to do this on a mixer because the friction will melt the chips, do it by hand).
Roll the cookie dough into a 1 1/2-inch wide log. Spray a sheet of parchment paper and wrap the cookie dough log with the greased parchment paper. Freeze until set, about an hour.
Cut frozen dough into portions that are about 1 1/8 inch thicker than the baking cups you're using, Place portions back in the freezer, working one at the time to keep the dough chilled.
After rolling the dough to 1 1/8 inch (thickness of two nickels together), place back in the freezer to chill. This is going to make a little bit easier for you to handle the dough. Make sure to keep the rolled cookie dough in between two sprayed parchment papers.
Spray the bottom of a nonstick standard muffin tray. Take a round cookie cutter that’s about twice the size of the cup mold of the muffin tray you’re using and fit the cookie dough over molding.
Bake at for 12-15 minutes, depending on thickness. It is crucial to let cookies sit and cool still on the cup mold for about 15 minutes, otherwise they'll break when removing.*Because they so delicate, you will have some broken cups but no worries you can use them as a garnish for whatever filling you use.