In a large bowl and with an electronic mixer on medium-high, beat the egg whites and cream of tartar until stiff peaks form. (about 2 minutes). Then place in the refrigerator.
Combine the flour, powder sugar, baking powder and salt in a large bowl.
In another bowl, whisk together the milk, melted butter (cooled), vanilla, and egg yolk (only 1).
Stir the milk mixture into the flour mixture.
Gently stir one-third of the beaten egg whites into the flour-milk mixture. Then gently fold in the remaining egg whites. (Be careful not to over mix, it is completely fine to have white parts still.)
Lightly spray griddle and ring molds (or cookie cutter shapes) with nonstick spray.
Turn griddle to medium-low heat. Fill 2/3 of the ring molds (or cookie cutters) with batter. Cover the ring molds with a clear lid until the batter rises to the top.
Cook for about 5 minutes or until the bottom is golden. With a spatula and tongs, carefully flip the rings. (Takes practice, but you'll get it!). Cook the other side for about 5 minutes or until the bottom is golden.
TIP: Turn oven to 150°F and keep pancakes warm until ready to serve.
Serve with your choice of fruit and syrup!