Slice the overripe banana into large chunks and place inside a glass mixing bowl.
Mash the banana by using the potato masher to press the banana against the bowl walls.Continue this process until the entire banana is mushed to the desired consistency.
First, transfer the mashed banana to an airtight container.
Then, cover the top of the bowl tightly with food wrap.
Label the date on the outside of the container and store in the fridge for 2-3 days.