Butter and flour a 9"x5" loaf pan and set aside.
In a medium bowl, combine 1½ cups flour, 1 tsp baking powder, ½ tsp salt, 1 Tbsp cocoa powder, 1 Tbsp cinnamon, 2 tsp ginger, ½ tsp nutmeg, and ¼ tsp allspice.
In a large bowl, beat together 1 cup sugar, ¼ cup brown sugar, ⅔ cup vegetable oil, ⅓ cup pumpkin pie filling, 2 eggs, and 1 tsp vanilla extract to blend.
Add the dry ingredients and stir until just blended.
Pour the batter into the prepared pan and smooth the top with a spatula. Bake for 40 - 45 minutes or until a toothpick inserted into the center comes out clean.
Allow to cool for at least 10 minutes before unmolding the cake. Place on a wire rack to cool completely. Optionally dust with powdered sugar and cut into slices for serving.