01 - Peel the bananas and slice them into ½-inch rounds. Arrange in a single layer on a parchment-lined baking sheet.
02 - Place the baking sheet in the freezer for at least 2 hours, or until the banana slices are completely solid.
03 - Transfer the frozen banana slices to a food processor or high-powered blender. Blend on high, scraping down the sides as needed, until smooth and creamy, about 2 to 4 minutes.
04 - If desired, add vanilla extract, cocoa powder, nut butter, or cinnamon and blend briefly to incorporate evenly.
05 - Serve immediately for a soft-serve texture, or transfer to an airtight container and freeze for 1 hour for a firmer scoopable consistency.