Preheat the oven to 325ºF. Lightly grease your loaf pan.
Combine the butter, sugar, vanilla extract, baking powder, baking soda, and salt in a large bowl. Mix by hand until smooth, about 2 minutes. Or use a stand or hand mixer on low speed for 1-2 minutes, until the mixture is smooth.
Stir in mashed bananas, honey, eggs, and sourdough starter discard. Combine until smooth, though there might be small lumps of banana. Add all-purpose flour, 1/2 cup at a time, stirring in between. Then add nuts or chocolate chips, if using.
Pour the banana bread mixture into the prepared loaf pan. Smooth the top and let rest at room temperature for 10 minutes before baking.
Bake for 45-60 minutes, or until a toothpick inserted into the middle of the loaf comes out clean. If banana loaf gets too brown, cover it with foil during baking.
Allow bread loaf to cool for 10 minutes in the pan before removing and slicing to serve.
Video
Notes
A 100% hydration sourdough starter works best for this recipe.Ingredient Note:Egg-Free Banana Bread: use a substitute from this egg substitutes list.Vegan Banana Bread: replace the egg with a flax eggs (2 tablespoons ground flax + 5 tablespoons water), use coconut oil instead of butter, and maple syrup instead of honey for a plant-based version.TFN Pro Tips:
The riper the banana, the sweeter your bread will be! I love using very dark, overly ripened bananas.
Don't over stir the batter, stir until the ingredients are just combined - small lumps are normal.
Storing Instructions:
Store leftovers in an air-tight container at room temperature for up to 5 days.
For longer storage: place in a freezer safe container for up to 3 months in the freezer.