Mix the eggs, sugar, flour, oil, sparkling water, again flour and baking powder together in this order. Spread the dough on a baking sheet and bake at 180 degrees on the middle rack for about 20 minutes until light brown.
Let cool down a bit and then cover with the drained mandarins. Mix the icing according to the instructions and pour over the mandarins. Mix the sour cream, sweet cream, cream stiffener and vanilla sugar together and spread on top of the cake topping. Put in a cool place.