Preheat the oven to 350 F.

Spray a 9×5 loaf pan with baking spray.

In a large mixing bowl, whisk together the pumpkin puree, brown sugar, sourdough starter, applesauce, eggs, and vanilla extract.

In a medium mixing bowl, whisk together the flour, pumpkin pie spice mix, salt, baking powder, baking soda.

Gently fold the flour mixture and the chopped walnuts into the pumpkin mixture. Fold until just barely combined. Overmixing will cause tough bread.

Pour the batter into the prepared pan and evenly spread out.

Sprinkle some chopped walnuts on top, if desired.

Bake for 45 minutes, and then tent the top with foil.

Bake for an additional 15-25 minutes, or until a toothpick inserted in the center comes out clean. If you have an internal probe thermometer, the center needs to be 190 F to be done.

Cool on a wire rack, in the pan, until cool.

Carefully remove from the pan and enjoy!