Arrange a rack in the middle of the oven and heat to 350°F. Coat a 9x5-inch loaf pan with cooking spray; set aside.

Place 2 cups granulated sugar, 1 (15-ounce) can pumpkin purée, ½ cup vegetable or canola oil, and 3 large eggs in a large bowl and whisk until smooth and combined. Add 1 tablespoon pumpkin pie spice, 1 ½ teaspoons baking powder, ¾ teaspoon baking soda, and ½ teaspoon kosher salt, and whisk to combine. Add 2 ¼ cups all-purpose flour and fold it in with a rubber spatula until just combined. Pour the batter into the prepared pan and spread into an even layer. Sprinkle with ¼ cup roasted pumpkin seeds, then gently press them into the batter to ensure they stick.

Bake until a toothpick comes out mostly clean with a few moist crumbs attached, 65 to 85 minutes. Let cool 10 minutes in the pan, then transfer to a cooling rack and let cool completely.