In a medium bowl, combine flour and baking powder. Stir in milk and egg yolk until smooth.
In a large glass or metal mixing bowl, beat egg whites until stiff peaks form. Fold 1/3 of the whites into the batter, then quickly fold in remaining whites until no streaks remain.
Heat a lightly oiled frying pan over medium high heat. Pour or scoop the batter into the frypan, using approximately ¼ cup for each pancake. Cook until pancakes are golden brown on both sides; serve hot.