Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Mix 160 g flour and cocoa. Add 100 g butter in pieces, icing sugar, 1 pinch of salt and egg. Knead everything first with the dough hooks of the mixer, then quickly with your hands until smooth.
Cover the dough and chill for about 30 minutes.
Place nuts on a baking tray and roast in a hot oven for 5-10 minutes until golden brown, turning from time to time. Take them out and rub the skin off. Coarsely chop the nuts.
Grease a tart mould with a lifting base (approx. 24 cm Ø) and dust with flour. Roll out the dough to a round shape (approx. 28 cm Ø) on a little flour. Line the tin with the dough, press the rim into the grooves, cut any excess rim straight.
Prick the bottom several times with a fork. Cover with baking paper and fill in the pulses. Pre-bake on the lowest shelf in a hot oven for 10-15 minutes. Remove the legumes together with the baking paper and continue baking for about 10 minutes.
Remove and let it cool down.
Break chocolate into pieces. Heat the cream, remove from the heat and melt the chocolate in it. Let the chocolate cream cool down a little, then fill into the tart. Chill for at least 4 hours, preferably overnight.
As soon as the chocolate cream begins to set, sprinkle the nuts on top. Sort the raspberries, wash them if necessary. Sprinkle on the cake. Serve with crème fraîche.