Preheat the oven to 350°F (175°C). Grease a 9×5-inch loaf pan and line with parchment paper.
In a large mixing bowl, whisk together eggs, brown sugar, white sugar, and vanilla until smooth. Add pumpkin purée, oil, and sourdough discard. Mix well.
In a medium bowl, whisk together flour, cinnamon, ginger, nutmeg, salt, baking powder, and baking soda.
Add the dry ingredients to the wet and stir just until combined. Don’t overmix.
Pour the batter into the prepared pan and smooth the top of the batter.
Bake for 60–70 minutes, or until a toothpick comes out clean or with a few moist crumbs.
Cool in the pan for 30 minutes, then transfer to a wire rack to cool completely before slicing.