Mix your chocolate pudding and cup of milk together till pudding is dissolved.
Chop up your peanut butter cups while pudding is setting up a bit.
Fold your cool whip into the pudding till combined, and then add 2/3 of the chopped up peanut butter cups.
Gently mix in, and pour into pie crust. Top with the remaining peanut butter cups.
Depending on how you like it, you could either chill in the refrigerator, or in the freezer for a few hours. I froze mine so it would slice easily and not be too soft.