1. Put first 5 ingredients (through salt) in a large bowl and stir with a whisk; make a well in the center. Put egg yolks and milk in a medium bowl and stir with a whisk until blended. Pour the milk mixture into the well of the dry ingredients. Using a wooden spoon, stir just until the batter is mixed. Do not overmix (a few tiny lumps of flour may remain).
2. In a small bowl, beat the egg whites with a hand mixer just until soft peaks form. Gently fold the egg whites into the batter.
3. Preheat a large nonstick pan. Add 1 teaspoon of the butter and heat over medium-high heat. Reduce heat to medium. Using 1/3 cup for each pancake, pour the batter into the pan, leaving 1 inch between pancakes. Cook until tiny bubbles form on the surface of the batter, about 2 minutes. Turn the pancakes and cook until the other side is golden brown, about 2 more minutes. Keep warm.
4. Add the remaining butter to the pan, and continue cooking until you run out of batter. Serve pancakes immediately on warmed plates, with the syrup and preserves on the side.