Put 10 cups of puffcorn into a large bowl.
Melt white chocolate melting wafers in the microwave following the directions on the package.
Stir in shortening.
Pour over puffcorn and stir to coat.
Sprinkle powdered funfetti cake mix over the puffcorn and stir to coat.
Add additional sprinkles, if desired.
Spread the funfetti cake batter puffcorn on a piece of waxed paper to cool and set.