1. Bake cake according to package directions.
2. When the cake has cooled, crumble it in a large bowl.
3. Mix nutella well into cake crumbs, microwaving the nutella first if necessary. Add more or less nutella depending on preference.
4. Using your hands roll each mixture into quarter size balls and lay on cookie sheet lined with wax paper.
5. Chill in freezer for at least thirty minutes.
6. Using a double broiler, melt chocolate chips.
7. When smooth, add butter.
8. Using a toothpick or lollipop stick, dip cake balls in chocolate and immediately add sprinkles.
9. Freeze for another 30 minutes until chocolate has hardened.