Position a rack in the lower third of the oven and heat the oven to 350ºF. Butter and flour a 10-inch tube pan or 12-cup bundt pan, preferably nonstick. Tap out any excess flour.
Sift together the flour, baking powder, salt, cinnamon, ground ginger, nutmeg, and cloves; set aside. Separate the eggs, putting the yolks in a small bowl and the whites in a large mixing bowl.
Using a hand mixer or a stand mixer with the whisk attachment, cream the butter on medium speed until smooth, about 1 minute. With the mixer on low speed, gradually add the vanilla and the brown sugar, about 1/2 cup at a time. When all the brown sugar has been added, stop the mixer, scrape down the sides, and cream the mixture on medium speed until light and fluffy, about 3 to 4 minutes.
Use a fork to lightly beat the egg yolks; then, with the mixer on low speed, add them slowly to the butter-sugar mixture. Scrape down the sides of the bowl, increase the speed to medium, and beat for 1 minute. On low speed, add the pumpkin purée, oil, and fresh ginger. Beat until smooth.
Using a rubber spatula, stir in one-third of the flour mixture, and continue stirring just until the flour disappears (don't beat or overmix). Repeat, adding the remaining flour mixture in two more passes. Scrape down the sides of the bowl and set it aside.
Add a pinch of salt to the egg whites and beat with an electric mixer just until they hold soft peaks. Gently but thoroughly fold them into the batter. Spoon the batter into the prepared pan, spreading it evenly with a rubber spatula. Bake until the cake springs back when touched with a fingertip and a pick inserted into the center of the cake comes out mostly clean with a few moist crumbs clinging to it, 45 to 50 minutes. Set the pan on a rack to cool for 10 minutes. Carefully run a paring knife around the inside edge of the pan. Invert the cake onto the cooling rack and gently remove the pan. Let cool completely. (If you're making the cake ahead, wrap it now). Just before serving, use a fine sieve to sift the confectioners' sugar over the cake. Cut into 3/4-inch slices and serve with a scoop of ice cream, if you like.