Preheat oven to 375°F. Grease a 9x5 loaf pan and line it with parchment paper (let the paper hang over the edges) for easy removal. Set aside.
Combine the flour, pumpkin spice, baking soda, and salt with a whisk in a medium bowl. Set aside.
Combine the pumpkin, granulated sugar, and brown sugar with a whisk in a large bowl. Beat in eggs, oil, and vanilla extract. Gradually whisk in the flour mixture until it is smooth and free of lumps.
Bake for 50 to 55 minutes, until a toothpick inserted in the center comes out clean. At around the 30-minute mark, loosely cover the top of the bread with foil to prevent overcooking. Pour the batter into the prepared loaf pan and use a spatula to smooth the top evenly.
Allow to cool for 10 minutes, then slice and serve warm, or allow to cool completely.