Years ago, i was at a street fair, and someone was selling a machine that was specifically for that. Insert frozen banana, 2 minutes later, out comes banana " ice cream"
I never bought the machine, but looked around online and was able to do it in my food processor.
need 3 or 4 ripe bananas.
Peel, cut in chunks and freeze
add frozen bananas to food processor along with some lemon juice ( maybe tsp or two)
Process until smooth and creamy.
Surprisingly has the texture of ice cream and healthy too.
I found it to be good, but not as addicting as the real thing ( got sick of it after one serving)
Im sure it would be great with chocolate syrup on it though :)