Serves 6. Line coeur a la creme mould with muslin/cheesecloth. In a large bowl whip the creme fraiche until it holds soft peaks. Alternatively, beat the double creme with the cream cheese. In another bowl, whip the egg whites until stiff. Stir about a quarter of the egg whites into the creme fraiche then fold the mixture into the remaining egg whites. Spoon the mixture into the mould and cover with plastic wrap. Set it on a dish and leave to drain in the refrigerator for at least 8, or up to 36 hours. An hour or two before serving, turn the cremets out onto a serving dish. Arrange the raspberries or strawberries around the cremets. Serve it with separate bowls of sugar or vanilla sugar and the remaining creme fraiche or creme Chantilly.