Step 1In a large bowl whisk the flour, baking powder, cinnamon, allspice and ginger.
Step 2In another bowl, combine the pumpkin, milk, egg yolks, brown sugar, butter and salt.
Step 3Add the liquid ingredients all at once to the dry, stirring just to blend; the batter should be slightly lumpy.
Step 4Beat the egg whites until they are stiff but not dry; fold the whites into the batter.
Step 5Heat a lightly oiled griddle or heavy skillet over medium high heat. For each pancake, pour one-fourth cup of batter onto the hot griddle, leaving space between the pancakes. When bubbles cover the surface of the pancakes and the undersides are browned, turn the pancakes over and cook for two minutes more. Dust with powdered sugar just before serving.