Preheat your waffle maker.

In a large mixing bowl, combine egg yolk, sour cream, milk, and melted butter.

Beat on low speed until moistened.

Increase speed to medium and mix until smooth.

In a separate bowl, stiffly beat egg white.

Gently fold the beaten egg white into the batter.

Pour a rounded 1/2 cup of batter onto the preheated waffle grids.

Close the waffle maker and bake until steam no longer escapes (about 3-5 minutes).

Remove the waffle with a fork.

Garnish as desired.

Serve immediately and enjoy.