Preheat the oven to 350°F and set an oven rack in the middle position.
Generously grease two 8 x 4-inch loaf pans with butter and dust with flour (alternatively, use a baking spray with flour in it, such as Pam with Flour or Baker's Joy).
Whisk the flour, salt, baking powder, baking soda, cinnamon, salt, ginger, nutmeg, and cloves in a large bowl.
Whisk granulated sugar, brown sugar, eggs, and vanilla together in a medium bowl for about 35 seconds until a light yellow color. Add the pumpkin, oil, and buttermilk until whisk until combined.
Pour the pumpkin mixture into the dry ingredients and whisk together. There will be a few lumps and it will be thick.
Pour batter evenly between the two prepared loaf pans. Spread out the tops with a spatula.
Bake for 44-54 mins. or until a cake tester inserted into the center comes out clean. Let the loaves cool in the pans for 15 minutes, then turn out onto a wire rack to continue cooling.