Put the warm water and the sugar in a bowl and sprinkle the yeast on top. Let stand for about 10 minutes. Stir well.
Add all other remaining ingredients except the egg-whites and mix until smooth and creamy. Cover with plastic wrap and let rise on a warm spot, free of any draft, for about 35-40 minutes.
Beat egg whites until fluffy and stiff (not dry!) and fold this into the batter.
Bake in moderately hot waffle iron until golden brown (about 3 to 5 minutes).
Can be used as a delicious dessert with ice cream, fresh fruit, and whipped cream.