
The most delicious and moist sourdough banana bread is a simple and classic quick-bread.
Preheat oven to 350 degrees.
Lightly grease a 9×5 loaf pan with butter.
Combine dry ingredients (flour, baking soda, baking powder, and salt) well in a medium bowl.
In a stand mixer or bowl, mix melted butter and brown sugar for five minutes until light and fluffy.
Add in eggs, vanilla, mashed bananas, and sourdough starter.
Fold in dry ingredients a bit at a time until just incorporated. Be careful not to over-mix.
Gently fold in any other add-ins you would like (pecans, walnuts, and chocolate chips or chunks, etc.).
Pour into a greased pan. You could also line your loaf pan with parchment paper.
Bake for 50-60 minutes. Test bread at 50 minutes with a toothpick or cake tester.
Allow to cool in the pan for one hour.
12-24 hours before you plan to make banana bread, mix together sourdough starter, melted butter, eggs, and flour. Cover with a towel or plastic wrap and allow to ferment at room temperature for 6 hours. Put the batter in the fridge and allow it to ferment for another 6-18 hours.