Make cake according to package directions and cool.
Mix in Nutella and incorporate cake and nutella evenly. Shape into 1" balls or use cookie scoop to make even sized cake balls. Roll in palm of your hands to smooth out. Place them on parchment paper lined cookie sheets.
Chill cake balls or freeze to be quicker. Then roll and coat into chocolate and sprinkle either using chopped hazelnuts or gold sugar sprinkles. You can also drizzle another color coating to decorate. Let set. Place in mini cupcake or candy paper cups and serve. I've noticed that if you do this the night before the flavors mingle better.