Bake cake according to directions for a 9x13 cake. Prick top of baked cake with fork. Pour kahlua over top. Let soak in (can be left overnight). Make chocolate mousse according to directions. Break up Skor bars into small pieces.
Assemble cake in large bowl. Crumble up half of cake and place in bottom. Layer half of mousse, half of whipped topping, half of Skor bars. Repeat layers. Serves 18.