Freeze your Reese's cups for at least a few minutes while you make the rest.
Combine the ingredients just like you would for any cookies. Mix all of the ingredients together starting with butter and sugars, then adding in eggs and cocoa. Add dry ingredients and mix.
Add the chocolate chips and mix them in.
Chop the Reese's cups into quarters and toss them in.
Mix for just a few seconds-just enough to mix them through but not to thoroughly mix them in. You don't want them to break completely apart if you can help it.
Roll into balls about 1 inch in size.
Bake at 375 degrees for 8-10 minutes. You want them baked but only just-not overdone. In my oven 9 minutes is just right. Yours may vary.