For the dough, mix flour, sugar, vanillin sugar, baking powder and 1 pinch of salt. Add butter in pieces and 6 tablespoons of ice-cold water. Knead first with the dough hooks of the hand mixer and then quickly with your hands to a smooth dough.
Wrap in foil and chill for about 1 hour.
Roast the nuts in a pan without fat and take them out. Coarsely chop toffees and nuts, except for some for decoration. Grease a tart mould with a removable base (26 cm Ø; or see tip on page 109) well, dust with flour.
Preheat oven (electric cooker: 175 °C/circulating air: 150 °C/gas: level 2). Roll out the dough between two layers of baking paper to a round shape (approx. 30 cm Ø). Place in the mould and press down at the edges. Prick the base with a fork.
Place baking paper on top, spread pulses brimful on top. Bake blind in the hot oven for about 15 minutes. Take out the paper with the pulses and continue baking for about 10 minutes.
For the cream, bring butter, cream, syrup and coffee powder to the boil while stirring. Boil down at medium heat while stirring continuously for about 25 minutes. Fold in nuts and toffees.
Pour the cream into the tart. Let it cool down. Cover and chill for about 1 hour. Decorate with remaining nuts.