A tender, ultra-moist banana bread subtly tangy from sourdough starter, jeweled with cranberries, and perfumed by bright orange zest for a festive winter loaf.
Preheat the oven to 350°F and line a 9×5-inch loaf pan with parchment paper.
In a medium bowl, whisk together the flour, baking soda, baking powder, and salt; set aside.
In a large mixing bowl, mash the bananas well with a fork.
Whisk in the melted butter, maple syrup, brown sugar, orange juice, and orange zest until combined.
Whisk in the eggs, then stir in the sourdough starter until well incorporated.
Fold the dry ingredients and the cranberries into the wet ingredients until just combined; do not overmix.
Pour the batter into the prepared loaf pan and bake for 55–65 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs. Begin checking at 55 minutes.
Let cool in the pan for 30–60 minutes before transferring to a wire rack to finish cooling.