To make sure that your banana bread is the best it can be, don’t bake until your fruit is very ripe and darkly speckled. This will all but guarantee deeply flavorful, moist results because as bananas ripen, their starch converts to sugar at an exponential rate.
We have scientific proof: When we sent bunches of bananas to a lab to have their fructose levels measured, the results showed that heavily speckled bananas had nearly three times the amount of fructose (the sweetest of the sugars in fruit) as less‑spotty ones.
And more fructose leads to tastier, more banana-y baked goods.
What’s more, sugar behaves like a liquid in baked goods, so breads and muffins made with ripe bananas will not only have better flavor but also be more moist.