HEAT oven to 350ºF.
PLACE 1 cookie in each of 30 paper-lined muffin cups. Prepare cake batter as directed on package; spoon 1 heaping Tbsp. over each cookie. (All batter will not be used.)
BAKE 14 min. or until toothpick inserted in centers comes out clean. Cool in pans 5 min.; remove to wire racks. Cool completely.
MICROWAVE marshmallow creme in medium microwaveable bowl on HIGH 15 sec. Gradually fold in whipped topping until blended.
REMOVE liners from cupcakes; cut cupcakes horizontally in half. Fill with whipped topping mixture. Serve upside-down. Keep filled cupcakes refrigerated.
