In a large bowl, combine the flour, vanilla sugar, sugar, and melted butter.

Separate the eggs, placing yolks in one bowl and whites in another.

Add the yolks to the flour mixture and mix well.

Whisk the egg whites until stiff peaks form.

Gently fold the whisked egg whites into the flour mixture until just combined.

Cover the dough and let it rest for at least 3 hours at room temperature.

Preheat and oil a waffle iron according to the manufacturer's instructions.

Pour the batter onto the hot waffle iron.

Cook until the waffles are lightly browned.

Serve immediately.