Prepare and bake your devil’s food cake as directed on your package. Cool completely.
Using a fork, carefully poke holes throughout the entire cake, about 1/2 inch apart.
Pour milks together into a large measuring cup. Stir to blend well. Pour evenly over entire surface of cake. The milk will absorb quickly into the cake.
Cover and place in refrigerator overnight or at least 5 hours.
Just before serving, Add chocolate syrup to whipped topping and stir until well blended. Spread evenly over cake.
If desired, sprinkle with chocolate shavings from a candy bar for garnish.