A "deep dish pie plate" refers to a baking dish that is deeper than a regular pie plate. It is used to make pies with a thicker filling or to hold more ingredients. Full definition
Grease a 9 - inch deep dish pie plate with cooking spray. (thespiffycookie.com)
It actually came out of the cake pan easily and I moved it to a pretty deep dish pie plate / dish and was able to take it to my brunch and reheat it before serving. (landsandflavors.com)
Add in the pecans and pour into a greased deep dish pie plate. (thewholegang.org)