Reduce the oven to 350°F and grease two 9-by-5-inch loaf pans. Mix the flour, salt, baking soda, baking powder, and spices in a large mixing bowl. In a separate mixing bowl, whisk together the sugars and canola oil until well combined. Then, whisk in the eggs, acorn squash puree, water, and vanilla extract. Pour the wet ingredients into the dry ingredients, folding until just combined.
3 ¼ cups all-purpose flour, 2 teaspoons baking soda, 1 teaspoon baking powder, 1 teaspoon salt, 2 teaspoons cinnamon, 1 teaspoon allspice, ½ teaspoon nutmeg, ½ teaspoon ginger, ½ teaspoon cloves, 1 ½ cup granulated sugar, ½ cup brown sugar, 1 cup canola oil, 4 eggs, ⅔ cup water