A famous French upside-down apple tart made by covering the bottom of a shallow baking dish with butter and sugar, then apples and finally a pastry crust. While baking, the sugar and butter create a delicious caramel that becomes the topping when the tart is inverted onto a serving plate. The tart was created by two French sisters who lived in the Loire Valley and earned their living making it. The French call this dessert tarte des demoiselles Tatin, "the tart of two unmarried women named Tatin. "