Combine 1 cup milk, bananas, and vanilla extract in a blender or food processor. Blend until very smooth and creamy, about 60 seconds on a blender's full speed. If the blades are catching, add more milk, just a splash at a time, to get the ingredients moving. Serve immediately, or transfer to a shallow dish and freeze for 30 minutes to firm it up and make it more scoopable (in a deep container it will take longer).
Transfer to an airtight container to freeze any leftovers, then let stand at room temperature for 15 minutes or so to soften before breaking up ice crystals with a fork, stirring well, and then scooping.
Notes
Make-Ahead ReminderDon't forget you have to Pre-Freeze Banana Slices to ensure you have ripe bananas on hand for whenever your ice cream cravings strike.Storage
Banana ice cream can typically be stored in the freezer for 1 to 2 months while maintaining decent quality. However, it's best to consume it within a few hours of making for optimal flavor and texture.