Preheat the oven to 350°F. Butter a 9-inch loaf pan.
Whisk together the flour, salt, baking soda, baking powder, cinnamon, nutmeg, allspice, and cloves in a small bowl.
Beat the butter, sugar, and oil on high speed in the bowl of a stand mixer fitted with the paddle attachment, scraping down the sides and bottom of the bowl a few times, until light and fluffy, about 1 minute.
Add the pumpkin puree and mix until combined. Add the eggs, one at a time, and mix until just incorporated. Mixing on low speed, slowly add the flour mixture and 2/3 cup water and mix until just combined.
Spread the batter into the prepared pan and bake until a toothpick inserted into the center comes out clean, 1 hour to 1 hour 15 minutes.
Let cool in the pan on a wire rack for 10 minutes. Remove from the pan and let cool completely.