Place cous cous, butter, sugar, water, pine nuts, raisins, almonds and hazelnuts in a mixing bowl. Thoroughly combine all the ingredients, cover and let rest for at least ½ an hour. Butter a ramekin to prevent sticking. Firmly pack some cous cous mixture in the ramekin and invert onto an individual dessert plate, so that the form of the cous cous is released from the ramekin. Sprinkle with icing sugar. Repeat for other individual plates and serve.