HEAT oven to 350°F.
PREPARE cake batter as directed on package; stir in 1-1/2 cups crushed cookies. Spoon batter into 24 paper-or foil-lined muffin cups.
BAKE 18 to 20 min. or until toothpick inserted in centers comes out clean. Cool in pans 10 min.; remove to wire racks. Cool completely.
TOP cupcakes with COOL WHIP and sprinkle with remaining crushed cookies just before serving.