1. 1. Prepare your baking dish and preheat the oven: Start by preheating your oven to 350 F (175 C). Lightly grease a 9×13 inch baking dish with butter or cooking spray. This prevents sticking and ensures easy removal of the bake once it’s done.

2. 2. Combine wet ingredients: In a large mixing bowl, whisk together your active sourdough starter, pumpkin puree, granulated sugar, 1/4 cup packed light brown sugar, eggs, 1/4 cup melted butter, and vanilla extract until the mixture is smooth and well combined. Ensure there are no lumps of sugar remaining.

3. 3. Mix dry ingredients: In a separate medium bowl, whisk together the all-purpose flour, baking powder, baking soda, ground cinnamon, ground nutmeg, ground ginger, and salt. Make sure all the spices are evenly distributed throughout the flour.

4. 4. Combine wet and dry mixtures: Gradually add the dry ingredient mixture to the wet ingredient mixture, stirring gently until just combined. Be careful not to overmix; a few small lumps are perfectly fine. Overmixing can lead to a tough texture in the final bake.

5. 5. Pour into baking dish and prepare topping: Pour the batter evenly into your prepared 9×13 inch baking dish. In a small bowl, combine the 2 tablespoons melted butter and 2 tablespoons light brown sugar for the topping. If using, stir in the chopped pecans or walnuts. Sprinkle this topping evenly over the batter in the baking dish.

6. 6. Bake the breakfast bake: Place the baking dish into the preheated oven and bake for 30-35 minutes. The bake is ready when a wooden skewer or toothpick inserted into the center comes out clean, and the edges are lightly golden brown. The top should appear set and slightly firm to the touch.

7. 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 slicing and serving. This allows the bake to set properly and makes for cleaner slices.