Quickly knead confectioner’s sugar, butter, flour, egg, and vanilla pulp to asmooth dough and let rest for half an hour, covered, in the refrigerator.
Preheat the oven to 400 °F (200 °C).
Roast the hazelnuts briefly in a preheated oven, so that the skins will come off more easily when you grate them.
Grate off the skins.
Mix the hazelnuts, granulated sugar, and water, and caramelize over medium heat.
