RESERVE 1 Tbsp. graham crumbs. Mix remaining crumbs with butter; press onto bottom of plastic wrap-lined 9-inch square pan. Refrigerate until ready to use.
ADD boiling water to gelatin mix in small bowl; stir 2 min. until completely dissolved. Add ice; stir 2 min. or until thickened. Remove any unmelted ice. Beat cream cheese in medium bowl until creamy. Gradually beat in milk, then lime juice. Add gelatin; mix well. Whisk in 1 cup COOL WHIP. Pour over crust.
REFRIGERATE 6 hours or until firm. Cover with remaining COOL WHIP just before serving; sprinkle with reserved graham crumbs. Use plastic wrap handles to remove dessert from pan before cutting into squares.