Melt dark chocolate on a hot water bath. Pour 2 tablespoons into a small piping spout. Spray the inside of 4 glasses, keep about 1 teaspoon of chocolate left, chill glasses. Dip 4 small spoons into the melted chocolate, also refrigerate. For the drink, whip cream and mascarpone with whisks. Stir in liqueur and the rest of the melted chocolate. Pour into the glasses, sprinkle with remaining chocolate from the piping spout and serve decorated with the chocolate spoon