Yvan-David Lemoine of Manhattan's Fleur de Sel is just 22, but he's already spent seven years working in New York City's top pastry kitchens. That experience is clear in this sophisticated yet whimsical dessert. Lemoine poaches pears in wine and Concord grape juice, then sandwiches them between walnut macaroons with whipped Devon cream. The result: a clever, seasonal version of an old-fashioned whoopie pie.