Spray an 8" or 9" loaf pan with cooking spray and preheat your oven to 350º
Melt butter in a small saucepan or the microwave. Once melted, remove from heat and let cool slightly while you prepare the other ingredients.
Whisk together flour, baking soda, spices and salt in a medium sized bowl and set aside.
Using a whisk, whisk the sugars, melted butter, and vegetable oil together until combined. It'll start to separate immediately, but that's ok!
Add in the eggs and vanilla extract. Continue beating until well incorporated.
Add the pumpkin to the egg mixture and whisk until all the wet ingredients are blended together.
Pour the pumpkin mixture into the dry ingredients and using a whisk or a wooden spoon, mix until the batter is just combined and no flour streaks remain. Do not over mix!
Pour the batter into the prepared loaf pan.
Bake bread at 350° for about 60-70 min. Rotate the pan halfway through baking.
The bread is done when an inserted toothpick comes out clean.