Place the oven rack in the center and preheat to 350°F. Spray two 8 ½” x 4 ½” loaf pans with cooking spray and line with parchment paper. In a medium bowl, whisk together flour, brown sugar, granulated sugar, baking powder, baking soda, salt and pumpkin pie spice.
2 ¼ cups all-purpose flour, ¾ cup light brown sugar, ¾ cup granulated sugar, 2 teaspoons baking powder, 1 teaspoon baking soda, ½ teaspoon fine sea salt, 4 teaspoons pumpkin pie spice
In a separate large bowl, whisk together pumpkin puree, melted butter, vegetable oil, eggs and vanilla extract. (Be sure to use pumpkin puree, not pumpkin pie filling.)
15 ounces pure pumpkin puree, 8 tablespooons unsalted butter, ½ cup vegetable oil, 3 large eggs, 1 teaspoon vanilla extract
Gently fold the dry ingredients into the wet ingredients using a rubber spatula. Mix until just combined - do not over mix.
Divide batter evenly between the prepared pans and smooth the tops with an offset spatula. Bake for 55 to 65 minutes. Start checking for doneness at 50 minutes: the loaf should spring back when touched, and a toothpick inserted in the center should come out clean. If loaves brown too quickly, start checking around 40 minutes, tent loosely with foil. Let loaves cool in the pans for 15 minutes, then transfer to a wire rack to cool completely before frosting.