1. Prepare Your Baking Dish: Preheat your oven to 375 F (190 C). Lightly grease an 8×8 inch baking dish with butter or cooking spray. This prevents sticking and ensures easy removal of your bake.

2. Combine Wet Ingredients: In a large mixing bowl, whisk together the sourdough discard, pumpkin puree, granulated sugar, brown sugar, melted butter, eggs, and vanilla extract until the mixture is smooth and well combined. Make sure there are no lumps of sugar remaining.

3. Add Spices and Salt: Stir in the pumpkin pie spice, ground cinnamon, ground nutmeg, and salt into the wet mixture. Mix until the spices are evenly distributed, filling your kitchen with a wonderful aroma.

4. Incorporate Dry Ingredients: In a separate medium bowl, whisk together the all-purpose flour and baking soda. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix; a few small lumps are perfectly fine. Overmixing can lead to a tough texture.

5. Pour into Dish and Add Topping: Pour the batter evenly into your prepared 8×8 inch baking dish. If using, sprinkle the chopped pecans or walnuts over the top of the batter. This adds a lovely crunch and visual appeal.

6. Bake to Golden Perfection: Place the baking dish in the preheated oven and bake for 25-30 minutes, or until a wooden skewer or toothpick inserted into the center comes out clean. The top should be golden brown and the edges slightly set.

7. Cool and Serve: Once baked, remove the dish from the oven and let it cool on a wire rack for at least 10-15 minutes before serving. This allows the bake to set properly and makes for easier slicing.