How to Make It
In a small bowl, dissolve the yeast in the water. In a large bowl, stir the flour with the salt. Whisk in the yeast mixture, milk, butter, egg yolks and vanilla until smooth.
In a medium bowl, beat the egg whites until soft peaks form. Fold them into the batter and let stand for 20 minutes.
Preheat the oven to 225°. Heat and grease a waffle iron. Pour 1 1/4 cups of the batter into the iron and cook until the waffles are golden, 6 minutes. Transfer the waffles to the oven. Repeat with the remaining batter. Dust the waffles with confectioners' sugar, drizzle with the Belgian Chocolate-Fudge Sauce and serve.