Mix the jelly powder, 50 g sugar and 1/4 litre cold water, heat while stirring (do not boil!) until everything is dissolved. Pour into a bowl and let it cool down. Melt butter. Put the rusks in a freezer bag and crumble finely with a cake roll. Mix butter and crumbs.
Spread the bottom of a springform pan (26 cm Ø) with oil. Spread crumb mixture on it and press it to a flat bottom. Chill for about 1 hour. Stir cream cheese, 75 g sugar, vanillin sugar and lemon juice until smooth. Peel the mango and cut the flesh into thin slices from the stone. Whip the cream until stiff. When the jelly starts to gel, stir in first the cream cheese, then the cream. Fill about 1/3 of the cream into the springform pan and smooth it down. Cover with the mango slices and add the rest of the cream, smooth it down.
Whip the cream until stiff. When the jelly starts to gel, stir in first the cream cheese, then the cream. Fill about 1/3 of the cream into the springform pan and smooth it down. Cover with the mango slices and add the rest of the cream, smooth it down. Put the cake in a cool place for at least 2 hours. Cut into about 12 pieces and decorate with mango slices
waiting time approx. 3 hours