It is a speciality of Lorraine in north-east France, where the mirabelle is an important crop.
[1][2] The Dictionnaire de l'Académie française and the Oxford English Dictionary both give the probable derivation of the name as Mirabel, a fairly frequent toponym in the south of France.
[1][2] A tart made with mirabelles is traditional in Lorraine and its neighbour Alsace and is found in other parts of France.
[10][11] In Beaulieu-sur-Dordogne, Elizabeth David encountered a tarte aux mirabelles made with yeast pastry: "Those little round golden plums of early autumn on their light brioche-like base made an unexpected and memorable end to our outdoor feast".
[4] The traditional tarte aux mirabelles consisted solely of fruit, pastry and a little sugar sprinkled on top before cooking.