Preheat oven to 325° F (165° C). Grease a 9" x 5" loaf pan.
In a large mixing bowl, add eggs and mash bananas with the back of a fork until smooth.
Add starter, butter, sugar, and vanilla and continue to mix.
Stir in flour, baking soda, and salt. Include cinnamon if using. Mix until just combined.
Fold in chocolate chips or nuts if using.
Pour batter into prepared pan. Bang pan gently on the counter to settle the batter and release any excess air.
Bake for one hour or until the bread loosens evenly from the sides and a toothpick stuck in the center comes out clean. Allow to cool for 15-20 minutes before slicing.
ENJOY!
Notes
Prefer to make mini loaves? Adjust cook time for 4 mini loaf pans to 40 minutes.Out of an ingredient? Here are a few substitutions:
EGG: Swap one egg with ¼ cup oil OR swap ½ cup butter with 6 tablespoons oil
VANILLA EXTRACT: Swap vanilla extract with equal amount maple syrup
SUGAR: Swap sugar with light brown sugar (packed) OR swap 1 cup sugar for ¾ cup honey OR ¾ cup maple syrup OR ⅔ cup agave syrup OR 1 teaspoon stevia.