Grease a tart mould (26 cm Ø) with a removable base and dust with flour. Mix 250 g flour, icing sugar, vanillin sugar and 1 pinch of salt. Add the egg, 125 g butter in pieces and 1 tablespoon cold water. Knead first with a hand mixer, then briefly with your hands until smooth
Roll out on some flour round (about 32 cm Ø). Line the mould with it, pressing the edges into the grooves. Prick the bottom of the pastry several times with a fork. Chill for about 1 hour.
Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 25 minutes. Cool in the mould for approx. 10 minutes. Then remove from the mould and allow to cool completely
Coarsely chop the almonds, except for 2 tablespoons. Roast chopped and whole almonds separately without fat, cool
Boil 250 g butter, 400 g cream and syrup while stirring. Then simmer for at least 25 minutes over medium heat, stirring continuously, until the mixture is creamy. Immediately pour a thin layer onto the pastry base and spread. Sprinkle with chopped almonds and pour the remaining toffee cream on top. Let it cool down. Chill for about 3 hours.
Bring 200 g cream to the boil and remove from the heat. Break the chocolate into pieces, melt in the cream with plate-fat and stir. Let cool for about 20 minutes. Pour on toffee cream, smooth it down and sprinkle with whole almonds. Let it cool down. Chill for at least 2 hours