In a medium bowl, whisk together the milk and the egg yolks.
In a separate bowl, whisk together the dry ingredients.
In another bowl, use an electric mixer to beat the egg whites until stiff but not dry (this is an important step for the outcome of the texture of the pancakes).
Add the dry ingredients to the milk-yolk mixture, stirring to blend. DO NOT OVER-MIX. Gently fold in the beaten egg whites; they should remain somewhat distinct in the batter.
Add about 1 teaspoon butter or oil to a preheated griddle or skillet. Add the batter by heaping tablespoon, making sure to include some of the egg whites in each spoonful. Spread into a circle with the back of the spoon. Cook until lightly browned on the bottom, 3 to 5 minutes, then turn and cook until second side is brown. Serve, or hold in a 200° oven for up to 15 minutes.