3/4 c. cold milk
1 pkg. instant lemon pudding (4 serving size)
1/4 c. powdered sugar
8 oz. container of light Cool Whip, thawed
Pour cold milk into a large bowl; add pudding and powdered sugar. Stir with a wire whisk until blended smooth. Let stand for 5-10 minutes to let thicken a bit.
Stir in Cool Whip with a spoon (DO NOT USE A MIXER) until smooth. Frost cake.