1. Prepare Your Baking Pan: Begin by preheating your oven to 350 F (175 C). Lightly grease and flour a standard 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. This prevents sticking and makes for easy removal.

2. Combine Wet Ingredients: In a large mixing bowl, whisk together the sourdough discard, pumpkin puree, granulated sugar, melted butter, egg, and vanilla extract until the mixture is smooth and well combined. Ensure there are no lumps from the pumpkin or sugar.

3. Mix Dry Ingredients: In a separate medium bowl, combine the all-purpose flour, baking powder, baking soda, ground cinnamon, ground nutmeg, ground ginger, ground cloves, and salt. Whisk these dry ingredients together thoroughly to ensure they are evenly distributed.

4. Combine Wet and Dry Mixtures: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix the batter; a few small lumps are perfectly fine. Overmixing can lead to a tough bread texture.

5. Create the Chocolate Swirl: Melt the semi-sweet chocolate chips in a microwave-safe bowl in 30-second intervals, stirring between each, until smooth. Alternatively, you can use a double boiler. Pour about half of the pumpkin batter into the prepared loaf pan and spread it evenly. Drizzle about half of the melted chocolate over this layer.

6. Layer and Swirl: Top the chocolate layer with the remaining pumpkin batter, spreading it gently to cover the chocolate. Drizzle the remaining melted chocolate over the top. Use a butter knife or a skewer to gently swirl the chocolate into the pumpkin batter, creating a marbled effect. Be careful not to over-swirl, as you want distinct streaks of chocolate.

7. Bake the Bread: Place the loaf pan in the preheated oven and bake for 45-50 minutes, or until a wooden skewer inserted into the center comes out clean. The top should be golden brown and the edges should be pulling slightly away from the pan.

8. Cool and Serve: Once baked, remove the loaf pan from the oven and let it cool in the pan for about 10-15 minutes on a wire rack. This allows the bread to set. Then, carefully lift the bread out of the pan using the parchment paper overhang (if used) or invert it onto the wire rack to cool completely before slicing and serving.