Preheat oven to 350 degrees. Butter two 9-inch round cake pans, then line the bottoms with parchment paper. Butter the paper and dust with flour, tapping out the excess.
In a medium bowl, whisk together the flour, cinnamon, ginger, baking soda, baking powder and salt. In a large bowl, beat the eggs with the brown sugar, pumpkin and oil, using a hand blender at medium-high speed, until blended. At low speed, beat in dry ingredients just until smooth.
Scrape the batter evenly into prepared pans, then bake in the center of the oven about 40 minutes, or until cake tester or toothpick comes out clean.
Cool the cake in pans for 30 minutes, then invert onto a rack to cool completely. Peel off the parchment paper once cool.