Separate eggs. Beat the egg whites and 3 tablespoons of water until stiff, adding 100 g of sugar. Stir in egg yolks. Mix flour, starch and baking powder and fold into the mixture. Line a baking tray with baking paper and spread the mixture evenly on top. Bake the sponge cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 8 minutes.
Remove the sponge cake from the oven and turn it over onto a tea towel sprinkled with sugar. Remove the baking paper. Roll up the sponge cake from the long side and chill. Soak gelatine in cold water. Sort out the raspberries and put about 20 pieces aside for decoration. Mix yoghurt, 100 g sugar and coconut liqueur. Squeeze the gelatine well, dissolve carefully and stir in 3 tablespoons of yoghurt mass and stir into the rest of the yoghurt. Chill for 5-10 minutes. Whip cream until stiff. When the cream starts to gel, fold in cream first, then raspberries. Roll out the sponge cake and spread the cream on top. Roll up carefully and chill for about 3 hours.
Chill for 5-10 minutes. Whip cream until stiff. When the cream starts to gel, fold in cream first, then raspberries. Roll out the sponge cake and spread the cream on top. Roll up carefully and chill for about 3 hours. Dust the sponge roll with icing sugar and divide into 15 pieces. Halve some of the raspberries. Decorate pieces with raspberries and coconut chips
3 1/2 hours waiting time