Pears are the starting point for this easy-yet-elegant dinner-party dessert. The pears are poached in a syrup infused with vanilla beans, becoming tender enough to eat with a fork—or a spoon, all the better to scoop up the ice cream at the base of each dish. Store-bought candies, melted with heavy cream to make a sauce, and hazelnut nougat are delectable toppings. Poach the pears, prepare the sauce, and freeze the ice cream in the glasses before dinner, then assemble everything just before serving.