Preheat oven to 350 degrees. Grease two 4½ x 8½-inch loaf pans with butter or nonstick spray.

Combine flour, baking powder, baking soda, salt, cinnamon, and nutmeg in medium bowl; whisk to blend.

Using electric mixer, beat pure pumpkin and both sugars in large bowl until blended. Gradually beat in oil, then one egg at a time, then minced ginger.

Stir in a fourth of the dry ingredients, followed by a third of the buttermilk; repeat until dry ingredients and buttermilk are both mixed in. Divide batter among prepared pans.

Bake breads until tester inserted into center comes out clean, about 1 hour. Cool in pans. Sprinkle generously with confectioner’s sugar. If made one day ahead, cover; store at room temperature.