Tart

tart in its sweet version is a subset of the sweet pie. The Anglo-American tart can be traced to late medieval European innovations in pie pastry formulations, which made the crust tender through the addition of fat. In contrast to the tough, leak-proof flour and water crusts that dominated pie cookery at the time, these softer crusts were enticingly bitable and chewable. See pie and pie dough. They encouraged pies in which the diner simultaneously took in filling and crust to create complex combinations of taste and texture in the mouth.