I looked through a few recipes online and looked to see what I had in the cupboard and fridge and this is what I came up with. It was good, not too sweet but still pretty rich.
1 graham cracker crust
1 8 oz red fat cream cheese
1 cup peanut butter
1 small box instant vanilla pudding
1 cup milk
1/2 8 oz cool whip
Grated chocolate for topping
Mix cream cheese and peanut butter until combined. Add pudding and milk and mix, then add cool whip last. Spoon into pie shell, sprinkle with chocolate and refrigerate. You could use a chocolate crust too.