how do you bake an Apple pie with a pan inside??

My wife who is a little shy .... asked me to ask you guys.
She said she saw Doug H. with an apple pie in a pie tin. and she thought it came out of a DO ans asked how he got it out.
Then cam the idea that it could be cooked with the pot upside down except that would make it a little hard to turn on the coals. The idea is if it were upside down, then you could lift off the pot and the pan would be inside the top (which is upside down)? anyone tried this??
She uses parchment paper so she can pull out cakes and such for surving, and wondered if that is what he did.
I did not see it and don't remember if Doug's new trailer had an oven.
She said she saw Doug H. with an apple pie in a pie tin. and she thought it came out of a DO ans asked how he got it out.
Then cam the idea that it could be cooked with the pot upside down except that would make it a little hard to turn on the coals. The idea is if it were upside down, then you could lift off the pot and the pan would be inside the top (which is upside down)? anyone tried this??
She uses parchment paper so she can pull out cakes and such for surving, and wondered if that is what he did.
I did not see it and don't remember if Doug's new trailer had an oven.