In a medium bowl, combine flour, baking soda, salt, cinnamon, ginger, nutmeg, and allspice. Set aside. In a large mixing bowl, using a handheld or stand mixer fitted with a whisk or paddle attachment whisk oil, eggs, sugar, pumpkin puree, and vanilla on medium speed to combine. Add dry ingredients and stir just until combined. Do not overmix at any step. The batter will be thick.