From America's Test Kitchen Season 3: Quick Breads
Overripe bananas are a good excuse to make banana bread, but the loaf can be dry, heavy, and bland. We wanted a banana bread with deep banana flavor, plenty of moisture, and a nice, light texture. Very ripe, darkly speckled bananas contribute moisture as well as flavor to this bread (they’re sweeter, too); unripe ones will not work. Pureeing the bananas kept the bread from rising well, so instead we mashed them thoroughly by hand. For additional moisture we included yogurt, which contributed a nice tang without masking the flavor of the bananas. The quick-bread method of mixing—melting the butter and folding the wet ingredients into the dry ones—produced a golden brown loaf and delicate texture; when we tried creaming the butter and sugar first, the bread came out more like butter cake and wasn’t as golden brown. However, we found it was important not to overmix the batter; too-vigorous stirring led to overabundant gluten development that turned the loaf tough and dense.
Makes one 9-inch loaf
Greasing and flouring only the bottom of a regular loaf pan causes the bread to cling to the sides and rise higher. If using a nonstick loaf pan, on which the sides are very slick, grease and flour sides as well as the bottom.