How to make
Heat a glass of milk and add the yeast. Let the yeast sit for a while.
Melt the butter. Separate the yolks from the egg whites and beat the egg whites, until a white mixture is obtained.
In a large bowl, pour the flour, vanilla sugar and a little salt. Pour the melted butter, the yeast with the milk and the egg yolks.
Mix with a mixer, by adding milk a little at a time (or sparkling mineral water, if you like). You need to mix the dough very well, so that there are no lumps.
The batter should be thicker than pancake batter. Gently mix the beaten egg whites into the batter (by hand with the help of a spatula).
Leave the dough rest and rise at room temperature for a while. The volume of the dough should have doubled or even tripled. If you're in a hurry, you can only wait an hour, but if you can, leave the dough overnight.
Use butter to grease the waffle iron (which should be very hot). Bake the waffles, until they aquire a golden brown color.
The Belgian Waffles with Yeast are ready.
