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