The prune plum is the firm, oval, high-sugar drying plum of the European species Prunus domestica — above all the Prune d'Agen, the cultivar behind the classic French prune. Small, deep purple-black under a dusty bloom, its dense amber flesh parts cleanly from the stone and is too sweet and too solid to eat only as a dessert fruit: it is bred to be dried whole into the prune, and to hold its shape in a tart, a tagine or a braise. Fresh it is honeyed and lightly tart; dried it becomes the dark, chewy, deeply caramel-raisiny prune of baking, North-African cookery and Armagnac-soaked confections.