Preheat the oven to 350 degrees Fahrenheit. Prepare two regular loaf pans or 3 to 4 mini loaf pans with nonstick cooking spray.
Whisk together the dry ingredients: flour, baking soda, cinnamon, pumpkin spice, salt, baking powder, sugar, and brown sugar.
Combine the vegetable oil, eggs, pumpkin puree, and banana in a mixing bowl until blended. Add the dry ingredients and stir just until combined.
Stir in the nuts.
Divide the batter between the prepared baking pans.
Bake in the center rack of your oven for 45 to 60 minutes or until a toothpick inserted in the center returns clean. Cool in the pans for 5 to 10 minutes before removing to continue cooling on a wire rack.