For the butter cookie soft cake, separate the eggs. Beat the snow. Beat yolks with sugar and vanilla sugar until foamy, gradually add water and continue beating until creamy.
Mix flour and cocoa powder and stir into the yolk mixture alternately with the beaten egg whites. Spread the dough on a baking tray lined with baking paper and bake at 180 degrees for about 15-20 minutes.
Let sponge cool and spread with sour cherry jam. Whip the Creme Legere until stiff and fold into the thoroughly stirred QimiQ Vanilla.
Season to taste with sugar, VZ and lemon juice and spread on the sponge cake base with sour cherry jam and top with butter cookies.
Chill in the refrigerator. It is best to prepare the cake a day in advance so that the cookies have time to set and are not hard.