Finely grate the chocolate. Mix the flour, almonds, powdered sugar, 1 tablespoon of cocoa powder and the chocolate. Add the chopped butter and the cream. Quickly knead into a smooth dough. Form two rolls of the dough, wrap in plastic and chill for about 30 minutes.
Preheat the oven to 180°C (approximately 350°F). Line two baking sheets with parchment paper. Cut each roll into about 20 slices. Shape each slice into a ball and place on a baking sheet. Bake for about 15 minutes. Mix the sugar, vanilla sugar and remaining cocoa powder. While the cookies are still warm, roll them in the sugar mixture. Let cool on a wire rack and serve.