Using a blender or food processor, place frozen bananas in and pulse until it resembles ice-cream consistency. If the bananas are not creamy, add a splash of milk (1-2 Tbsp).
Add any flavor mix-ins you would like--peanut butter, chocolate chips, fresh fruit, nuts etc, and pulse until well mixed.
Serve immediately for a creamy texture. If you want to save the ice-cream for later, place in a freezer safe container and freeze. Note: the ice-cream may not be as creamy when it is frozen.
Notes
*You can add mix-ins on top instead of blending in if you desire.