Spicy Pumpkin Pound Cake

2 1/2 cups cake flour
1 1/2 teaspoons baking powder
1/2 teaspoon salt
1/2 teaspoon ground ginger
1/2 teaspoon ground nutmeg
1 1/2 teaspoons ground cinnamon
1/2 teaspoon ground cardamom
4 eggs, at room temperature, separated
1/2 teaspoon cream of tartar
1 cup unsalted butter, at room te mperature
1 tablespoon Bourbon whiskey or 2 teaspoons vanilla extract
2 cups lightly packed brown sugar
1 cup unsweetened pumpkin puree, canned or fresh
Powder sugar for dusting the cake
Preheat oven to 350°F. Position rack in lower third of oven. Spray a 10-inch tube pan or 12-cup Bundt cake pan with vegetable spray and set aside.
In a large mixing bowl, sift together the flour, baking powder, salt, ginger, nutmeg, cinnamon, and cardamom. Set aside.
Separate eggs. Place yolks in a small bowl and whites in a large mixin g bowl.
In another large bowl, beat the butter until smooth. Add the brown sugar a half-cup at a time beating well after each addition. Beat in Bourbon whiskey or vanilla and continue beating for about 3 minutes.
Beat the yolks with a fork then add to sugar mixture, one-third at a time. Using a rubber spatula, scrape down sides of bowl as you mix.
Add pumpkin puree and beat until smooth. With a wooden spoon, stir in 1/3 of the flour mixture. Beat just until dry ingredients are incorporated. Continue adding remaining flour in two batches. Set aside.
Add cream of tartar to egg whites and beat until soft peaks form. Gently fold whites into pumpkin batter.
Spo on batter into prepared pan. Gently spread batter evenly around pan. Bake for 45 to 50 minutes. Allow the cake to cool in the pan for 10 minutes, then invert onto a cake plate. Allow to completely cool. Dust with powdered sugar.