The day before, make the sweet dough by mixing the flour, 90 g of butter, 30 g of caster sugar, 1 egg, salt, vanilla sugar and ground almonds, like a shortcrust pastry. Work as short as possible and leave to rest in the refrigerator overnight.
The next day, roll out the dough to 4 mm thick, line a 26 cm diameter tart tin with it, buttered beforehand, leaving a slight ridge that you pinch between your thumb and forefinger. Let stand 1 or 2 hours. Preheat the oven to th. 7 (220°C).
Prick the bottom, cover it with a sheet of parchment paper, garnish it with pulses and cook for about 20 minutes. Leave to cool then remove the paper and the dried vegetables.
While cooking, prepare the filling:in a bowl, mix the caster sugar, the eggs, the fresh cream, then add the coffee and the melted butter, the brown sugar and the chopped walnuts. Mix well, pour into the pie shell and put back in the oven at 200°C (th.6) for 40 minutes.
Leave to cool, sprinkle with icing sugar and decorate with walnut kernels.