1 pkg. white cake mix
3 tbsp. Creme de Mint (or 1/2 tsp. mint extract & green food coloring)
1 can Hershey's fudge topping
1 lg. container Cool Whip
Green food coloring

Bake cake according to mix directions. Cool. Spread cooled cake with fudge topping. Mix Creme de Mint into Cool Whip plus appropriate amount of green food coloring. Spread Cool Whip over fudge topping. Refrigerate.