Recipe adapted from Simply Recipes
Overmixing the batter is the single fastest way to turn tender quick bread into dense, rubbery cardboard. When flour meets wet ingredients, gluten strands begin to form immediately, meaning that excessive stirring develops elasticity where you actually want a tender, crumbly cake crumb. Fold the all-purpose flour into the mashed bananas and melted butter only until no dry streaks remain, accepting a few small lumps rather than chasing absolute smoothness.
Baking soda requires both moisture and an acid to activate, and while ripe bananas provide that necessary acidity, the reaction starts the moment liquid touches the powder. Transfer the batter to the 350 degree Fahrenheit oven promptly after mixing to capture rising gases before they dissipate. Because ovens vary significantly in internal temperature, testing with a wooden toothpick inserted into the thickest part of the 8-inch by 5-inch loaf pan remains the only reliable indicator of doneness.