Preheat Oven to 350 degrees.
Brown 1/2 c. of salted butter in the cast iron skillet.
Combine dry ingredients: 2 c. flour, 1 tsp. baking soda, 2 tsps. baking powder, and 1 tsp. salt in a medium mixing bowl.
In a large bowl or a stand mixer, mix melted butter and 1/4 c, brown sugar.
Add in 2 eggs, 1 tsp. vanilla, 2 mashed bananas, 3/4 c. honey, and 1/2 c. sourdough starter.Â
Fold in dry ingredients a little at a time until just incorporated.
Gently fold in any other ingredients you would like (walnuts, pecans, raisins, chocolate chips or chunks, etc.).
Pour into the skillet used to brown the butter.
Bake for 50-60 minutes. At the 50-minute mark, insert a toothpick into the center of the bread. If it comes out with batter, continue baking, checking periodically, until the toothpick emerges clean—signaling a perfectly baked loaf.
Allow to cool in the skillet for approximately 20 minutes before cutting and serving. Enjoy!