For the fruity-exotic rhubarb-coconut cake, peel and slice the rhubarb and mix with 2 tablespoons of granulated sugar. Preheat the oven to 170 degrees Celsius.
Separate the eggs, beat the egg whites with 1/3 of the sugar until stiff. Beat the yolks with the remaining sugar and vanilla sugar until foamy. Stir in the buttermilk and gradually the flour sifted with the baking powder.
Fold in half of the snow. Spread on a baking tray. Fold the coconut flakes with the rhubarb into the remaining snow and spread on the dough. Bake in the preheated oven for about 40 minutes!