LINE 13x9-inch pan with foil, with ends of foil extending over sides of pan. Mix wafer crumbs and butter. Press firmly onto bottom of prepared pan; set aside until ready to use.
ADD milk to dry pudding mixes in medium bowl. Beat with wire whisk 2 min. or until well blended. Gently stir in half of the whipped topping. Spoon evenly over crust. Refrigerate 10 min. Add remaining whipped topping to sherbet; stir with wire whisk until well blended. Spoon evenly over pudding layer; cover.
FREEZE at least 3 hours or overnight. Use foil handles to remove dessert from pan before cutting into squares to serve. Store leftover dessert in freezer.
serving size = 1 square (62 g)