Knead 350 g flour, 250 g butter in pieces, 100 g sugar, vanilla sugar, 1 pinch of salt and egg with the dough hooks of the mixer to a smooth dough. Cover and chill for about 30 minutes.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer). Grease baking tray (approx. 35 x 40 cm) well and dust with flour. Roll out the dough on it and prick it more often with a fork.
Bake in a hot oven for 20-25 minutes. Take out, let cool down.
Heat 800 g cream in a pot. Caramelise 500 g sugar and 2 tbsp water in a large pan until golden brown (see page 70, fig. 1 + 2). Carefully add hot cream. Add 5 tbsp. butter.
Reduce to a creamy consistency over medium heat, stirring continuously, for about 35 minutes. Immediately spread evenly on the baked base. Put in a cool place for approx. 45 minutes.
Break chocolate into pieces. Heat 200 g cream in a pot. Add the chocolate. Melt it while stirring. Remove from the heat and allow to cool slightly while stirring. Spread evenly on the caramel mass and chill for approx. 1 1⁄4 hours.
Cut into pieces.