01 - Peel the bananas and cut them into 1-inch 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 high-speed blender or food processor. Blend on medium speed, pausing frequently to scrape down the sides, until the mixture becomes creamy and smooth.
03 - If desired, add vanilla extract, unsweetened cocoa powder, or nut butter to the blender. Continue blending until all additions are fully incorporated and the texture is uniform.
04 - Serve immediately for a soft-serve consistency, or transfer to a freezer-safe container and freeze for 1 to 2 hours for a firmer, scoopable texture.
05 - Top with fresh berries, chopped nuts, or dark chocolate chips as desired and serve promptly.