The only thing to do is to use them up!
Years ago when I worked onboard the Love Boat, crew members would routinely request bananas from the galley whenever they had a craving for baking. Bananas were plentiful in Africa... but they still went brown after a few days of being stored onboard. In such cases (and depending on the chef...) they were often up for grabs rather than getting tossed out with the garbage.
The ship was equipped with small crew kitchens called ripostos. (I have no idea if that is the correct spelling... I've never figured out where the term came from.)
Spelling aside, I was never a fan of cooking in these ripostos -- mainly because they never seemed to be up to my standard of cleanliness. Plus, we had a whole crew of kitchen staff who served us three meals a day. Nevertheless, I occasionally wanted to bake something. Anything.
I acquired a small oven (on par with the looks of a child's easy bake...) and somehow I was allowed to use it in my tiny cabin. Along with my own coffee maker, it allowed me to have a homey feel when I started to get claustrophobic about eating in the same dining room as hundreds of other people.
I love having no-fail recipes. My no-fail recipe onboard was an apple cake made with an insane amount of oil and a fridge milk-tart (admittedly, I failed numerous times on the latter one until I figured out the difference between corn starch and corn meal. DUH.) I don't think I had a no-fail banana bread recipe at the time, but eventually, I found one on land. This Banana Banana Bread one is in my favorites and is insanely quick and easy.
So quick and easy in fact that yesterday, after lunch, I commented to the sailor how rotten the bananas looked on the counter, and within minutes of him suggesting I make banana bread, the ingredients were mixed and in the oven.
An hour later.... Banana Banana Bread. Baked in and served on vintage Pyrex, of course.