Using a mixer, cream together peanut butter, cream cheese, and powdered sugar. Once fully combined, add whipped topping one cup at a time.
Chop Reese’s cups into small pieces. Add six chopped Reese’s cups to pie mixture. Stir with spatula. Add pie mixture to prepared Oreo crust. (Be sure to take the plastic lining out of prepared crust before adding pie filling). Add the rest of the chopped Reese’s cups to the top of pie.
Chill pie in refrigerator for at least 1 hour before serving. Enjoy!