Ripen bananas quickly in the oven
They say that you should buy bananas that are slightly green or hard. As you let them sit on your countertop, they’ll ripen to the perfect degree, or they’ll go bad immediately. Just keep an eye on the bananas and you should be fine.
However, if you want to eat a banana now, or if you want to make banana bread with overly ripened bananas (the riper the banana, the sweeter it is), then preheat your oven to 300° and stick the bananas in there. Let it bake for 5-10 minutes, checking on it every once in a while. When the peel develops black spots, it’s ready to eat.