Spray 3 (8-inch) cake pans with cooking spray. Preheat oven to 350 degrees.
Beat the eggs, water, and vegetable oil together until fully combined. Gradually whisk in the cake mix. Stir in ½ cup sprinkles. Divide the batter evenly among the prepared pans and bake for 20-25 minutes or until golden brown and a toothpick inserted into the center comes out clean. Let cool in pans for 10 minutes then remove to a wire rack to fully cool.
Trim the top domed part of each cake layer. Place one player on a cake plater, spread with frosting and repeat with the remaining layer. Frost the sides and top of the cake.
Decorate by applying sprinkles and piping on extra frosting.