For the shortcrust pastry, mix butter in pieces, flour, cocoa, 1 egg, 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 quark, 75 g sugar and crème fraiche with the whisks of the hand mixer. Stir in the remaining eggs. Add sauce powder and stir in. Let melted chocolate coating shrink and stir
Quarter the pears, peel them, remove the core, dice the flesh and stir into the quark mixture. Pour the quark mixture into the tart mould on the base, smooth it down and bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) on the bottom rack for 40-50 minutes until the mixture has set. After about 20 minutes, spread the nuts evenly on the tart. Remove the tart from the oven, place on a cake rack and allow to cool
waiting time approx. 1 1/2 hours