Make the frosting with butter, powdered sugar, vanilla, and heavy whipping cream
Divide frosting into 1 large bowl and 4 smaller bowls. Color the 4 smaller bowls.
Add crushed cereal to the larger bowl.
Place a large dollop of the cereal speckled frosting onto each of the cooled cupcakes.
Use a piping bag with a large star tip.
Place the color frostings along the sides of the piping bag.
Fill the center of the piping bag with the white icing.
Place a large swirl of this rainbow frosting on the top of each cupcake
Sprinkle with crushed cereal then enjoy!