Prepare 1 box white cake mix as directed, except substitute 3 tablespoons Creme de Menthe flavoring or liqueur, for 3 tablespoons water.
Pour into 13x9 inch pan and bake according to package directions.
Remove from oven and while HOT, poke holes in cake with fork. Then pour chocolate syrup over the top. Refrigerate (or freeze, if desired). After cooling, mix whipped topping with 2 tablespoons of creme de menthe and spread on cake. Keep refrigerated. Freezes great!!