Separate eggs. Beat the egg whites with the whisks of the hand mixer until stiff. Add salt, 75 g sugar and vanillin sugar. Stir in egg yolks. Mix flour, starch, baking powder and cocoa, sieve onto the egg mixture and fold in.
Spread the mixture evenly on a baking tray (32 x 39 cm) lined with baking paper. Bake in a preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: see manufacturer) for 8-10 minutes.
Take out the sponge cake and turn onto a tea towel sprinkled with sugar. Remove the paper and roll the sponge cake with the tea towel and let it cool down.
Soak gelatine in cold water. Chop whole milk chocolate and melt over a warm water bath. Whip 200 g cream until stiff. Chop 320 g chocolate bars finely. Mix cream cheese and 50 g sugar.
Stir in liquid chocolate. Squeeze out the gelatine, dissolve and mix with 4 tablespoons of chocolate cream cheese. Stir into the remaining chocolate cream cheese. Fold in cream and chocolate bar.
Unroll the sponge cake, spread the cream on it, roll it up and chill it for at least 2 hours. Chop dark chocolate. Heat 100 g cream in a small pot. Add chocolate and coconut fat and mix to a glaze.
Place the sponge roll on a cake rack and cover with icing. Finely chop the remaining chocolate bars and spread them on top. Place the roll on a cake plate and chill for at least 30 minutes.