The evening is drawing to a close. Your guests have eaten well, conversed with enthusiasm, appreciated the wine. Now it's time to bring out your pièce de resistance: a truly divine chocolate delicacy. Here's an awe-inspiring selection of intense delights. There are full-blown desserts such as a dark chocolate tart or a gianduja dacquoise, or petits fours to serve with coffee: cigars, marquises and madeleines. Your only difficulty will be deciding which to try first.