Place the bananas and remaining ingredients in the bowl of a food processor. Blend or process until the mixture is the consistency of soft-serve, stopping to scrape down the sides and break up any clumped banana chunks as needed.
Serve immediately or transfer to a freezer-safe container and freeze for up to 1 month. If serving from the freezer, allow the nice cream to sit at room temperature for a few minutes, or until it becomes scoopable.
