For use in banana bread, the bananas need nearly all their starch converted to sugar to provide the fruity, non-cloying sweetness that plays foil against the hint of savory that keeps the dish balanced. Although banana bread is a resourceful way to utilize over-ripe bananas, getting rid of near-rotten fruit should never be the goal of any dish. You have the most control over banana bread's quality when you use ripe bananas and give them a little push to accelerate the ripening process. The insulated environs of the oven provide the best conditions for increasing the ethylene production that hastens banana ripening.
Heat the oven to 300 degrees Fahrenheit. Line a sheet pan with parchment paper.
Separate the bananas from the bunch and lay them on the sheet pan a couple inches apart from each other. Place the pan in the oven.
Bake the bananas until the skins blacken, about 30 minutes for medium bananas and 40 minutes for large. Take the pan out of the oven.
Cut the tips off the bananas and squeeze them into a bowl or into the bread batter when they reach room temperature.