Preheat the oven to 180 degrees Celsius or 356 degrees Fahrenheit.
Beat the egg whites with some sugar until it forms a firm snow.
Melt the white chocolate in a water bath (it takes longer than dark chocolate) and then let it cool down.
Mix together the soft butter, sugar and vanilla sugar until creamy and then add the milk and the yogurt.
Add the molten white chocolate and fold in the egg snow carefully. At the end mix flour and baking powder and add it to the mixture.
Grease the baking tray with enough butter to prevent sticking of the cake on the form. Then fill the mass into the form and bake it in the oven for 40 minutes, until it's fluffy and moist.
For the glaze mix the pomegranate juice with the powdered sugar and pour it over the cake.