Place the frozen raspberries in a sieve over a bowl and allow to defrost (collecting the juice).
Brush a cake plate with some oil. Place a cake ring or the rim of a springform pan (18 cm Ø) on top. Roughly chop the whole chocolate coating and melt in a hot water bath. Remove from the bain-marie.
Add almonds and cornflakes and stir well. Fill into the cake ring and press down as a base. Chill for about 1 hour.
Soak gelatine in cold water. Whip cream until stiff and chill. Mix mascarpone, quark, 60 g sugar and vanilla sugar. Squeeze the gelatine and dissolve at low heat. Stir in 3-4 tbsp. mascarpone cream, then stir everything into the rest of the cream
Fold in the cream. Fold half of the raspberries briefly into the cream. Pour onto the chocolate base and smooth it down. Chill the cake for at least 4 hours, preferably overnight.
Mash the remaining thawed raspberries and the juice collected and pass through a sieve. Bring raspberry puree and 1 tablespoon of sugar to the boil. Stir starch and 1 tablespoon cold water until smooth. Stir into the boiling puree and simmer for at least 1 minute while stirring. Let it cool down.
Shortly before serving, select fresh raspberries, wash if necessary and dab dry. Remove the cake from the cake ring. Spread the raspberries on the cake and drizzle with raspberry sauce. Cut the cake into pieces.