1. Preheat your oven to 350 F (175 C). Grease and flour a 9×5 inch loaf pan, or line it with parchment paper, leaving an overhang on the long sides to easily lift the bread out later.

2. In a medium bowl, whisk together the all-purpose flour, baking soda, and salt. Set this mixture aside.

3. In a large bowl, melt the unsalted butter. Add the granulated sugar and brown sugar to the melted butter and whisk until well combined and smooth. Beat in the eggs one at a time, then stir in the vanilla extract until fully incorporated.

4. Mash your ripe bananas thoroughly with a fork, then add them to the wet ingredient mixture. Stir in the unfed sourdough discard until just combined. The mixture might look a little lumpy from the bananas, which is perfectly fine.

5. Gradually add the dry ingredient mixture to the wet ingredients, mixing only until just combined. Be careful not to overmix, as this can lead to a tough banana bread. A few streaks of flour are okay.

6. Pour about two-thirds of the batter into your prepared loaf pan. Sprinkle half of the chocolate chips evenly over the batter. Pour the remaining batter over the chocolate chips, then sprinkle the rest of the chocolate chips on top. Use a knife or skewer to gently swirl the chocolate into the top layer of batter, creating a marbled effect.

7. Place the loaf pan in the preheated oven and bake for 50-60 minutes. The bread is done when a wooden skewer or toothpick inserted into the center comes out clean or with only a few moist crumbs attached. If the top starts to brown too quickly, you can loosely tent it with aluminum foil.

8. Once baked, remove the loaf pan from the oven and let the banana bread cool in the pan for about 10-15 minutes. Then, carefully lift it out using the parchment paper overhang or invert it onto a wire rack to cool completely before slicing and serving. This allows the bread to set and prevents it from crumbling.