Separate the eggs for the sponge cake base. Beat the egg whites and 3 tablespoons of cold water until stiff. Add 75 g sugar, salt and 1 packet of vanilla sugar. Stir in the egg yolk. Mix flour, starch, baking powder and cocoa and sieve onto the egg-sugar mixture. Fold in 2-3 portions. Pour the dough onto a baking tray lined with baking paper, smooth it down and bake in a preheated oven (electric cooker: 200 °C/ gas: level 3) for 10-12 minutes.
Remove from the oven, place on a damp tea towel sprinkled with 50 g sugar and remove baking paper. Wrap the protruding edges of the tea towel over the edges of the sponge cake. Leave to cool. In the meantime, wash, peel and quarter the pears, cut out the core and dice the pulp. Boil up apple juice, rest sugar and lemon juice. Add pear cubes and simmer for 2-3 minutes at low heat. In the meantime soak gelatine in cold water. Whip cream until stiff. Add the rest of the vanillin sugar. Put the cream in a cool place. Remove the pears from the stove. Pour into a mixing bowl. Squeeze the soaked gelatine and stir into the pears.
Whip cream until stiff. Add the rest of the vanillin sugar. Put the cream in a cool place. Remove the pears from the stove. Pour into a mixing bowl. Squeeze the soaked gelatine and stir into the pears. Place the mixture in a cool place until it begins to gel. Fold cream in portions under the pears and spread evenly on the pastry sheet (leave a 2 cm margin on one wide side of the pastry). Roll up the sponge cake from the wide side using a kitchen towel and put in a cool place for about 3 hours. Use a peeler to remove the chocolate from the rolls. Dust the sponge roll with icing sugar and sprinkle with chocolate. Cut into 12 cake pieces. Serve decorated with lemon balm and pear wedges as desired
Place the mixture in a cool place until it begins to gel. Fold cream in portions under the pears and spread evenly on the pastry sheet (leave a 2 cm margin on one wide side of the pastry). Roll up the sponge cake from the wide side using a kitchen towel and put in a cool place for about 3 hours. Use a peeler to remove the chocolate from the rolls. Dust the sponge roll with icing sugar and sprinkle with chocolate. Cut into 12 cake pieces. Serve decorated with lemon balm and pear wedges as desired