Preheat oven to 350˚F.
Place flour, cinnamon, baking soda, nutmeg, ginger, all-spice, salt, and baking powder in a mixing bowl and whisk together.
Place oil and both sugars in another mixing bowl and whisk together.
Add eggs to the sugar mixture, 1 at a time, scraping down the sides of each bowl after each addition, and beat together until well combined.
Stir in vanilla.
Pour one third flour mixture into the wet mixture and mix together. Add half the pumpkin puree and continue to mix together.
Add another third of the flour mixture and whisk together. Stir in the remaining pumpkin puree and mix together.
Whisk in the remaining flour mixture and stir until no lumps remain (batter will be thick, but still pourable).
Pour the batter into a lightly greased, 9 inch bundt pan and bake for 60 to 70 minutes or until a toothpick comes out clean when inserted into the center of the cake.
Allow the cake to cool for 15 minutes before inverting onto a cooling rack. Then allow cake to finish cooling, about 2 hours.