Preheat oven to 350 degrees F. Line 8.5 x 4.5 inch loaf pan with parchment paper.
Mix dry ingredients together in a large bowl and set aside.
Whisk pumpkin puree, oil, eggs, sugar, and brown sugar together in another bowl until smooth. Then whisk in sourdough discard, vanilla, and maple syrup until smooth.
Stir dry ingredients into wet, just until no flour streaks remaining.
Pour batter into an 8.5 x 4 inch loaf pan that is lined with parchment paper and bake for about 1 hour and 15 minutes or until toothpick comes out clean.
Let bread completely cool in the pan on a wire rack.
Once cool, use a small fine mesh sieve to lightly dust loafwith powdered sugar