01 - Peel the bananas and cut them into ½-inch thick rounds. Arrange the slices in a single layer on a parchment-lined baking sheet and freeze for at least 2 hours until completely solid.
02 - Transfer the frozen banana slices to a food processor or high-powered blender. Blend on high, pausing to scrape down the sides as needed, until the mixture becomes smooth and creamy with a soft-serve consistency, about 2 to 4 minutes.
03 - For added flavor, blend in vanilla extract, unsweetened cocoa powder, or nut butter and pulse briefly until evenly incorporated.
04 - Serve immediately for a soft-serve texture, or transfer to an airtight container and freeze for 1 additional hour for a firmer, scoopable consistency.