Crush 16 cookies; toss with the butter. Press onto the bottom of an ungreased 9 inch square dish. In a mixing bowl, beat the cream cheese, peanut butter and 1 c. powdered sugar until smooth. Fold in half the whipped topping. Spread over crust. Sprinke with peanut butter cups.
In another mixing bowl, beat the milk, pudding mix, and remaining powdered sugar on low speed for 2 minutes. Fold in the remaining whipped topping. Spread over peanut butter cups. Crush remaining cookies; sprinkle over the top. Cover and chill for at least 3 hours.