Step-by-step Instructions for One-Ingredient Ice Cream. (http://www.thekitchn.com)
1) Pick a couple of ripe bananas. They should be sweet and soft but not too mushy.
2) Peel the bananas and cut them into coins
3) Freeze the banana pieces for at least an hour or two.
4) Put the pieces into a food processor or blender.
5) Blend on high. Initially they will look crumbly and piecemeal. The mixture will probably get stuck a lot. Keep scraping down the bowl. Suddenly, as you keep blending, you will see a change.
6) The bananas turn creamy!
7) (Optional) Now is the time to add a scoop of peanut butter, honey, or anything else you care to mix in.
8) The ice cream will be the texture of soft-serve, but if you freeze again in an airtight container, it will get harder and more like regular ice cream.
This is the best thing ever. I like to add a couple of tablespoons of raw cacao powder, and some nut butter. You can also melt some dark chocolate to drizzle on top and it will go hard as it freezes.
I like to buy too many bananas and freeze them when they get ripe so I have extras in the freezer for smoothies and soft serve.