1 ½cups(350g)mashed bananas (about 3 medium bananas)
½cup(140g)sourdough starter, fed or discard
½cup(100g)neutral-flavored oil (see note)
½cup(106g)packed light brown sugar
2large(100g out of shell)eggs
1 ¾cups(249g)all-purpose or whole wheat flour (see note if using whole wheat)
Preheat the oven to 350 degrees F. Line a 9X5-inch loaf pan with parchment paper and lightly grease with cooking spray (I cut a strip of parchment paper and line the bottom and two long sides). Set aside.
In a large bowl, whisk together the bananas, sourdough starter, oil, brown sugar, granulated sugar, egg and vanilla until very well-combined.
Add the flour, baking soda, baking powder, salt and cinnamon. Mix with a rubber spatula until just combined and no dry streaks remain. Don't over mix.
Pour the batter into the prepared pan. Bake for 50-60 minutes until the top springs back lightly to the touch and a toothpick inserted in the center comes out clean.
Remove the bread from the pan and let cool on a wire rack.
Pan Size: this recipe makes too much batter for a smaller 8 1/2 X 4 1/2-inch loaf pan, so make sure the pan is 9X5-inches. (For high elevation baking where batter can rise quicker and sometimes overflow, you might want to reserve some of the batter and bake in a mini loaf pan or 2-3 muffins. I live at 2,500 feet and this bread does not overflow in the oven, but I haven't tested it at high elevation). Oil: use a neutral-flavored oil like canola, vegetable, grapeseed, melted coconut oil (refined coconut oil doesn't have a strong coconut flavor) or other oil without a strong flavor profile. I haven't tried subbing part of the oil with applesauce, but you can experiment. You can also use melted butter. If doing so, decrease the salt by 1/4 teaspoon. In my testing, the bread rises less well when using melted butter and the crumb has a slightly greasier texture. For that reason, I prefer using oil.Whole Wheat: when using whole wheat flour in this recipe, I recommend using white whole wheat (hard or soft wheat) - or a wheat berry or flour like kamut or einkhorn. Those varieties are less dense and dark than using red whole wheat.