Melt the butter. Grind the rusks. Mix both with 50 g sugar and, except for 2 tablespoons, place in a greased springform pan (24 cm Ø). Press firmly and chill for about 1 hour. For the mousse, soak gelatine in cold water.
Drain the apricots and collect the juice. Put about 10 halves aside. Puree the remaining apricots and 100 ml of juice. Mix with cottage cheese, lemon juice, remaining sugar and vanillin sugar. Squeeze gelatine well, dissolve lukewarm and stir into the prepared cream. Put it in a cool place until it begins to firm up. Whip 150 g cream until stiff. As soon as the cream begins to firm up, fold in the cream and spread on the rusk. Cover with the remaining apricots and chill. Whip the rest of the cream until stiff.
Whip 150 g cream until stiff. As soon as the cream begins to firm up, fold in the cream and spread on the rusk. Cover with the remaining apricots and chill. Whip the rest of the cream until stiff. Fill into a piping bag with star-shaped spout and decorate the cake. Serve the cake with the rest of the rusk crumbs and decorate with small sugar pearls and mint to taste. Makes about 12 pieces