In the past, pie was the dessert most frequently ordered in restaurants in the United States. Although pies as we know them were perfected by American and British bakers in the nineteenth century, covered pies were served by the Greeks and Romans more than two thousand years ago.
Most pies consist of a layer of pastry dough or a crumb crust mixture lining a sloping-sided pan. The crust may be baked blind (without a filling) and filled later, or the filling may be baked with the crust, with or without a top crust. A pie is always served from the pan in which it was baked. A deep dish pie has a fruit filling and only a top crust and is baked in a casserole or other deep baking dish. Cobblers, buckles, grunts, and slumps, the first cousins of pies, have fruit fillings and are baked in shallow dishes with top crusts only. These crusts may be made from pastry dough, baking powder biscuit dough, or a thinner version of the biscuit dough that is poured over the filling before baking.