The day before, prepare the sweet shortcrust dough by quickly mixing the flour, 90 g butter, 30 g caster sugar, 1 egg, salt, vanilla sugar, and ground almonds. Work the dough briefly and chill overnight in the refrigerator.
Next day, roll out to 4 mm thick. Line a buttered 26 cm tart tin, forming a pinched ridge. Rest 1-2 hours. Preheat oven to 220°C (th. 7).
Prick the base, cover with parchment paper, add dried beans or pulses, and bake 20 minutes. Cool, then remove paper and weights.
Prepare the filling: Whisk 70 g caster sugar, 2 eggs, and cream. Stir in coffee, melted 40 g butter, brown sugar, and chopped walnuts. Pour into shell; bake at 200°C (th. 6) for 45 minutes.
Cool completely, dust with icing sugar, and decorate with walnut kernels.
