Preheat your oven to 350°F and set the rack in the lower-middle position. Lightly grease a 9×5-inch loaf pan, then line the bottom with a piece of parchment paper.

In a medium mixing bowl, whisk together the flour, pumpkin spice, cinnamon, baking soda, baking powder, and salt.

In a large bowl, whisk the pumpkin puree, sugar, and brown sugar until smooth. Add the eggs, oil, and vanilla, and mix until combined.

Gradually add the dry mixture to the wet mixture, and whisk until the batter is smooth and no dry flour remains.

Pour the batter into the prepared pan and smooth the top. Bake for 60-75 minutes, making sure to cover it loosely with foil halfway through to ensure the top doesn't get too brown. The bread is ready when a toothpick inserted in the center comes out clean (crumbs are okay, but there should be no wet batter).

Let the loaf cool in the pan for 10 minutes, then slide a knife around the edges and invert the bread onto a wire rack. Allow the bread to cool for another 5-10 minutes, then slice and serve.