For the short pastry, separate 1 egg. Chill the egg white. Mix butter in pieces, flour, cocoa, egg yolk, salt, vanillin sugar and 75 g sugar first with the dough hooks of the hand mixer, then with your hands to a smooth shortcrust pastry. Roll out to a circle (approx. 28 cm Ø) on a well floured work surface
Place the dough in a greased, flour-spread tart mould (approx. 24 cm Ø; with lift-off base), raise the rim and press down. Prick the base several times with a fork and chill for approx. 45 minutes
Roughly chop the chocolate coating. Melt in a bowl over a warm water bath. Remove from the stove and allow to cool slightly
Mix cream cheese, 75 g sugar and crème fraiche with the whisk of the hand mixer. Stir in 4 eggs. Add sauce powder and stir in. Allow melted chocolate coating to shrink and stir. Pour the cream cheese mixture into the tart mould on the base and bake in the preheated oven (electric range: 175 °C/ convection oven: 150 °C/ gas: level 2) on the lower rack for approx. 40 minutes until the mixture has set. Remove from the oven, place on a cake rack and allow to cool
Beat 2 egg whites until stiff, pour in 100 g sugar. Spread the beaten egg whites loosely on the cold tart with the back of a spoon, leaving about 2 cm free at the edge. Bake the tart in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for 5-10 minutes until golden brown and serve soon
waiting time approx. 1 1/2 hours