The first time I made this was about 45 years ago- when I was first married- we went to the fair and watched a demo for a "Vita Mix" machine a 12 in one machine. I still have the same stainless steel wonder blender. Shiny as ever and I love it.
Peel and cut bananas in chunks. Place in freezer on tray in single layer. Leave in freezer about 1 hour. Place banana chunks or pieces in bowl of your blender and pulse several times to break into smaller pieces, then turn on and run for about 5 minutes, stopping to scrape down the sides of blender. The bananas will start to look like soft serve ice cream Scrape bananas into a freezer container and freeze for 15 minutes or eat right away.
Note: I like to make this this with raspberries or blueberries too. The last time I made this I used peaches. This is so good. I usually eat it plain but have been known to drizzle caramel topping and chopped nuts over top. LOL