1. Prepare your baking pan and preheat the oven: Start by preheating 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 loaf out later. This prevents sticking and ensures a clean release.

2. Whisk together the dry ingredients: In a large bowl, combine the all-purpose flour, baking soda, salt, ground cinnamon, ground nutmeg, ground ginger, and ground cloves. Whisk them together thoroughly until well combined. This ensures the leavening agents and spices are evenly distributed throughout the batter.

3. Combine the wet ingredients: In a separate medium bowl, whisk together the sourdough discard, canned pumpkin puree, granulated sugar, light brown sugar, melted and cooled unsalted butter, eggs, and vanilla extract. Whisk until the mixture is smooth and all ingredients are fully incorporated.

4. Combine wet and dry mixtures: Pour the wet ingredient mixture into the bowl with the dry ingredients. Stir gently with a spatula or wooden spoon until just combined. Be careful not to overmix; a few lumps are perfectly fine. Overmixing can lead to a tough loaf. If adding chocolate chips or nuts, fold them in now.

5. Transfer to the loaf pan and bake: Pour the batter evenly into the prepared loaf pan. You can gently tap the pan on the counter a few times to release any large air bubbles and level the top.

6. Bake until golden and cooked through: Bake for 50-60 minutes, or until a wooden skewer or toothpick inserted into the center of the loaf comes out clean. The top should be golden brown and spring back when lightly touched.

7. Cool before slicing: Once baked, remove the loaf from the oven and let it cool in the pan for about 10-15 minutes. Then, carefully lift it out of the pan using the parchment paper overhang (if used) or invert it onto a wire rack to cool completely. Slicing too early can cause the loaf to crumble.