Have you tried making ice cream using frozen bananas yet? As long as you keep a few frozen bananas in your freezer, you can have ice cream in a few minutes. Great for a sudden ice cream craving. ;)
You'll need a blender for this. A Vitamix is perfect but other blenders will do the job as well. Just break your banana into quarter size pieces or smaller before freezing. The smaller the pieces, the less work for your blender.
This is one of my favorites.