300 g flour    
300 ml milk
180 g butter
70 sugar
2 eggs
1 teaspoon baking powder
Pinch of salt
Pinch of vanilla sugar

In a bowl, mix flour, sugar, salt and baking powder. Melt the butter in a saucepan, add egg whites, milk, vanilla sugar, and stir. Add to the flour and mix until the batter is uniform. Carefully add beaten egg whites. Cook in a waffle pan until golden brown. Serve with berries and melted chocolate, fried bananas and jam, or ice cream, whipped cream, maple syrup, or othe sweet toppings to taste. Sprinkle with powdered sugar.  
Try also savory toppings – tuna, cheese salad, avocado, tomato, cucumber, eggs, and bacon.