All you need are frozen bananas and what I used to make it chocolate:
2-3 c. frozen bananas, slightly thawed
1/4 cup water
2 T. unsweetened cocoa powder
1/8- 1/4 stevia powder, to taste
As bananas thaw for about 10 minutes or more (and even more if using a food processor), dissolve cocoa powder and stevia in water. I put it in a container and shook it up really well.
See Healthy One-Ingredient Ice Cream