A crostate is an Italian tart, or pie.
It is usually not very tall, though occasionally deep dish ones are made. It is meant to stand on its own, outside a pie pan, when baked.
The shell is made of pasta frolla (occasionally pasta sfoglia can be used for a crust) and is either free-formed on a cooking sheet, or for large pies, in a pie mould whose bottom and sides come away: “uno stampo da crostata con fondo removibile.”) Small crostate tarts may be made in small moulds. When cooked free-form on a cookie sheet, the edges are folded up around the filling (which will be a thick filling, not a runny one.)
The crust is baked separately first (baked blind), poked with a fork, then the filling put in.
If it’s a cream filling, the crust is completely baked, because that is all the baking it will have. If it’s a filing such as apples or a fruit that requires cooking, the shell will be baked just a bit first. And may have a top, lattice crust added as well before being put back into the oven for the complete cooking. Ones with a marmalade or jam filling usually have a top crust and are aren’t pre-baked; they baked with the filling on them and any lattice top crust on.
Any metal pie shell frame used is removed before serving.
Savoury crostate can be made, too.
Language Notes
Crostate comes from the Italian verb “crostare”, meaning “to crust, to cook something until it crusts up.”
Sources
Doti, Irene. Italian Desserts: Dolce Memories. New York: Basic Books. 1998. Page 90.