Start by preheating the oven to 350 degrees Fahrenheit and greasing a 9x5 loaf pan.
In a large bowl, stir together the oil, sugar, molasses, eggs, and pumpkin puree. Also, stir in the sourdough starter and vanilla extract.
In a separate bowl, mix together your flour, salt, baking powder, baking soda, and all your spices. Then add your dry ingredients to your wet ingredients and stir until combined.
Finally, fold in your chopped walnuts and raisins.
Once the batter is prepared, transfer it into your prepared pan and bake it in the oven for 60-65 minutes. It is done when you can stick a paring knife into the center of the loaf and pull it out completely clean.
When completely baked, remove it from the oven and cool it in the pan for 15 minutes before turning it out and allowing it to cool completely on a rack. Once completely cooled, slice and serve!