Start the banana bread mixture about 4 hours before baking. You can also, let this batter ferment longer overnight. If fermenting overnight, make the batter right before bed and bake in the morning.
Begin melting the butter and let it cool slightly before adding it to the mixture. Mix together the flour, room temperature - fed and active sourdough starter, sugar, butter, and vanilla. After mixing, cover and let sit for 4 to 6 hours.
After fermentation, preheat the oven to 350F. Prepare the 8x8 baking pan by cutting parchment paper to cover the bottom and sides. I do this for easy removal of the banana bread. You can also butter the pan, but the banana bread wont come out as easily.
Add the remaining ingredients. Add the eggs, salt, baking powder, and baking soda to the fermented batter and mix well.
Pour the batter into the prepared pan and sprinkle with cinnamon and sugar.
Bake for 45 to 50 minutes or until a toothpick comes out of the center of the banana bread clean.
Allow the banana bread to cool in the pan before removing. Enjoy your sourdough banana bread!
