If we have an abundance of overripe bananas, I like to cut them up into small slices and freeze them in a zip bag. Then when we want a frozen dessert, I take the slices and blend them in a food processor for a bit until it is a little mushier (using a utinsel to clean the sides when it's not blending well). Then, it's a great time to put in cinnamon/pumpkin spice and/or peanut butter, and I blend once more and it's ready to serve.
It's a suprisingly easy and tasty dessert that doesn't have dairy and doesn't need extra sugar. If you don't slice the bananas before freezing, they are harder to blend. Should probably eat the bananas within maybe a month or so of freezing.