Preheat oven to 350 degrees
Place a large sieve over a large bowl
Add the dry ingredients to the bowl through the sieve; the flour, baking soda, salt, pumpkin pie spice, brown sugar and granulated sugar. This will help breakup any chunks and create a really nice, light overall texture
If the salt does not fit through the sieve then add it after sifting the other ingredients and just whisk it in
In a separate bow, whisk together the eggs, pumpkin, sour cream, melted butter and oil
Slowly mix the dry ingredients into the wet ingredients using a whisk
Do not over-mix! Only mix until everything is evenly incorporated
Spray two 9.5 x 5 inch loaf pans with cooking spray
Pour the batter evenly between the loaf pans so they are about 2/3 full
Bake at 350 degrees for about 50-60 minutes or until the middle is set; test this by inserting a toothpick and if it comes out clean then it is done, if it comes out wet then it needs to bake longer
Allow the baked loaves to cool for about 5-10 minutes and remove from the pan and allow to cool completely on a cooling rack