Using a standing mixer, or large bowl and hand mixer, beat the butter, powdered sugar, vanilla extract, and heavy whipping cream until combined, smooth and stiff peaks form
Scoop about 1 1⁄2 C of frosting into another bowl and mix in a few drops of the purple food coloring
Add a few drops of neon green into the main bowl of frosting
Scoop 1 1⁄2 C of the green frosting into one side of the large piping bag
Scoop the purple frosting into the other side of the large piping bag
Decorating the cauldrons directions
Using the medium piping bag with the two frosting colors, pipe frosting into the middle of the cauldron
Sprinkle a few of each type of sprinkle around on the frosting
Place the fondant stick into the side of the frosting
Enjoy!