Mix flour, baking powder and 75 g sugar. Add the egg and 100 g butter in pieces. Knead first with the dough hooks of the hand mixer, then briefly with your hands until smooth. Put the dough in a cool place for about 30 minutes
Grease a springform pan (26 cm Ø) and sprinkle with breadcrumbs. Roll out the dough on a little flour round (approx. 30 cm Ø). Line the tin with the dough, pressing the edge of the dough up about 2 cm. Prick the dough base several times. Refrigerate the baking tin again
Melt 250 g butter and 250 g sugar while stirring. Stir in nuts and milk. Remove from the heat and let cool down for about 10 minutes. Spread nut mixture on the shortcrust pastry. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/gas: level 3) on the 2nd rack from below for approx. 25 minutes (if necessary, cover with parchment paper for the last 5 minutes). Cool down, remove from the edge and turn over
Coarsely chop the chocolate coating and melt in a hot water bath. Coat the short pastry side and the edge of the cake with it. Let it dry. To serve, cut the cake into approx. 20 pieces, possibly turning every 2nd piece over. Decorate with cream and nuts