For the coconut chocolate slices, melt the chocolate in a water bath. Mix flour, baking powder, cocoa, sugar and salt. Add eggs, syrup, butter and chocolate and mix everything together.
Spread the dough on a baking tray lined with baking paper and bake at 180 °C for about 20-25 minutes. Allow to cool.
For the cream, soak gelatin in cold water. Mix yogurt with sour cream, sugar, vanilla sugar and grated coconut. Dissolve gelatin according to package directions and stir into yogurt mixture.
Whip the cream until stiff and fold into the yogurt mixture. Spread on cake, refrigerate and let set. Cut into small slices.