Pie

Pie \pai\ , noun;

Yum! (source)

Pie meaning "pastry" dates to the 1300's from Middle Latin pie ("meat or fish enclosed in pastry"), which might be related to Middle Latin pia ("pie, pastry"). It could also be related to pica ("magpie") because of the bird's habit of collecting random objects.

Fun fact: Pie has no related words outside of English except Gaelic pighe, which was borrowed from English.
Another fun fact: Fruit pies didn't start to appear until the 1600's.