HEAT oven to 350ºF.
PREPARE cake batter as directed on package; pour into greased and floured 2-L ovenproof bowl. Bake 1 hour or until toothpick inserted in centre comes out clean. Cool in bowl 15 min. Loosen cake from side of bowl; invert onto wire rack. Remove bowl; cool cake completely. Cut cake horizontally in half. Place flat layer on plate.
CRUSH 7 large Oreo Cookies to form coarse crumbs; mix with Cool Whip. Spread 1 cup of the Cool Whip mixture onto cake layer on plate; top with remaining cake layer. Frost with remaining Cool Whip mixture.
DECORATE with remaining ingredients as shown in photo. Refrigerate leftovers.