Separate eggs. Beat the egg white and 3 tbsp. water until stiff, adding 100 g sugar. Stir in egg yolks. Mix flour, starch and baking powder and fold into the mixture. Line a baking tray (32 x 39 cm) with baking paper and spread the mixture evenly on it.
Bake the sponge cake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 8 minutes. Roast grated coconut in a pan without fat. Remove the sponge cake from the oven and turn it over onto a tea towel sprinkled with sugar. Peel off baking paper. Roll up the sponge cake from the long side and chill.
Soak gelatine in cold water. Cut the mango pulp from the core, peel and dice. Mix sour cream, 100 g sugar, coconut milk and vanillin sugar. Dissolve squeezed gelatine in a small pot. Stir in 3 tablespoons of sour cream and add to the rest of the cream. Chill for about 10 minutes until the cream starts to gel. Whip cream until stiff and fold in. Fold in mango pieces.
Unroll the sponge cake, sprinkle with liqueur and spread cream on top. Carefully roll up the sponge again and refrigerate for about 4 hours. Heat the jam, pass through a sieve and spread a thin layer on the roll. Roll the roll in the rasps, decorate with coconut chips and refrigerate until serving