1 large ripe banana
airtight, freezer-safe container
small food processor
1. Start with ripe bananas: They should be sweet and soft.
2. Peel the bananas and cut them into coins: It doesn't matter what shape or size the pieces are in, as long as they are chopped up into evenly-sized and somewhat small pieces.
3. Put the bananas in an airtight container: A freezer-safe glass bowl like this one is fine, or you can use a freezer bag.
4. Freeze the banana pieces for at least 2 hours: Freeze for at least 2 hours, but ideally overnight.
5. Blend the frozen banana pieces in a small food processor or powerful blender: Pulse the frozen banana pieces. We've found that a small food processor or chopper works best.
6. Keep blending — the banana will look crumbly: At first the banana pieces will look crumbled or smashed. Scrape down the food processor.
7. Keep blending — the banana will look gooey: Then it will look gooey, like banana mush. Scrape down the food processor.
8. Keep blending — the banana will look like oatmeal: It will get smoother but still have chunks of banana in it. Scrape down the food processor.
9. Watch the magic happen! Suddenly, as the last bits of banana smooth out, you'll see the mixture shift from blended banana to creamy, soft-serve ice cream texture. Blend for a few more seconds to aerate the ice cream. (If adding any mix-ins, like peanut butter or chocolate chips, this is the moment to do it.)
10. Transfer to an airtight container and freeze until solid: You can eat the ice cream immediately, but it will be quite soft. You can also transfer it back into the airtight container and freeze it until solid, like traditional ice cream.