Beat the eggs, 125 g sugar and salt with the whisk of the hand mixer until thick and creamy (8-10 minutes). Mix the flour, starch, almonds and baking powder and stir into the egg foam alternately with the mineral water. Pour onto a baking tray lined with baking paper and smooth down. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: not suitable/ gas: level 3) for 10-12 minutes. Then immediately turn the sponge onto a damp tea towel sprinkled with sugar.
Cover with a 2nd damp tea towel and let it cool down. Soak gelatine in cold water. Sort the raspberries. Mix mascarpone, yoghurt, kombucha, 60 g sugar and vanillin sugar. Squeeze out the gelatine, dissolve and mix with 3 tablespoons of cream. Stir into the remaining cream. Spread the cream on the sponge cake plate, leaving a 1 1/2 cm wide rim all around. Spread the raspberries over the cream, except for a few for decoration. Roll up the plate lengthwise. Chill for 3-4 hours.
Stir into the remaining cream. Spread the cream on the sponge cake plate, leaving a 1 1/2 cm wide rim all around. Spread the raspberries over the cream, except for a few for decoration. Roll up the plate lengthwise. Chill for 3-4 hours. Cut the sponge roll into about 20 pieces. Decorate with icing sugar, pink sugar and the rest of the raspberries
waiting time approx. 3 hours