Mix the cream cheese with 300 g cream and the natural yoghurt and stir until smooth. Then stir in the sugar and vanilla sugar. Beat the rest of the cream with the pack of cream stiffener and fold in carefully. Crumble the ladyfingers finely (or cut them lengthways). Now layer the ladyfingers and the mixture, starting with the biscuits. You can also decorate with fruits if you wish. Finally, chill for 2 hours in the refrigerator.