Preheat oven to 350°. Spray a bundt pan with baking spray or butter and flour. Set aside.
Whisk the flour, baking powder, baking soda, cinnamon, allspice, nutmeg, ginger, cloves, and salt in a bowl. Set aside.
Mix pumpkin, buttermilk, and vanilla in large measuring cup and set aside.
In the bowl of a stand mixer or use a hand mixer, cream the butter and sugars until fluffy (about 3 minutes).
Add eggs and beat until incorporated.
Reduce speed to low and add the flour mixture to the pumpkin mixture, alternating (beginning and ending with flour mixture).
Pour batter into the prepared bundt pan. Bake for about 40-45 minutes or until a toothpick inserted in the center comes out clean (crumbs on the toothpick are okay but wet batter is not). Cool about 10 minutes in the pan. Remove from pan to a cooling rack and allow to cool completely
Sprinkle with confectioners' sugar if desired.