In tarte Tatin, apples are caramelized in butter and sugar before the tart is baked. The sugar combines with butter and the apples’ juices to form the dessert’s characteristic glossy caramel coating.
Tarte Tatin is an upside-down French tart. The apples and caramel go into the pan first, while the pastry is placed on top. During baking, the pastry cooks above the fruit; the finished tart is then inverted so the caramelized apples are exposed and the pastry becomes the base.
This arrangement distinguishes tarte Tatin from a conventional apple pie, whose pastry generally surrounds the filling. It also differs from blind-baking: the pastry is not pre-baked underneath the fruit. Traditional versions commonly use puff pastry, although recipes vary. The name is associated with the Tatin sisters and the Hôtel Tatin at Lamotte-Beuvron, though the dessert’s exact origin story has been debated.