
Preheat the oven to 350 degrees Fahrenheit. Line a 9 x 5 x 2.5-inch loaf pan with parchment paper and spray with nonstick cooking spray.
Add ½ cup melted salted butter and 1 cup granulated sugar to a large bowl and beat with a hand mixer or a stand mixer fitted with the paddle attachment until combined. Add 2 large eggs, ¾ cup pure pumpkin puree, ¼ cup sour cream, and 1 teaspoon vanilla extract and beat until combined.
In a medium bowl, whisk together 2 cups all-purpose flour, 2 teaspoons ground cinnamon, 1 teaspoon baking soda, ½ teaspoon baking powder, ¼ teaspoon ground nutmeg, and ¼ teaspoon ground cloves.
Add the flour mixture to the pumpkin mixture and mix until fully combined. Pour the batter into the prepared loaf pan.
Bake for 45-60 minutes, or until a toothpick inserted into the center of the loaf comes clean.