Best Ever Hotcakes recipe

2 eggs, separated
1 tablespoon granulated sugar
3/4 teaspoon salt
1 cup all-purpose flour, sifted
1 1/2 teaspoons baking powder
1/2 teaspoon baking soda
1 cup milk
1/3 cup sour cream
4 tablespoons butter, melted

Add sugar and salt to well beaten egg yolks. Sift and measure four, add baking powder and soda and re-sift. Add flour mixture and milk, to egg yolk mixture alternately, a bit at a time until all are added, (stir the whole time). Add sour cream and mix well. Add melted butter and mix well. Gently fold in stiffly beaten egg whites. Bake on hot griddle, turn only once when bubbles on the surface break.