Do you have a recipe like the one at Burger King? I haven't tasted it yet but it looks yummy. The one's I found on the internet don't look like it.
Why don't you go eat one, maybe you can figure it out from the taste and texture. It's probably a standard frozen cream pie with peppermint and peppermint patties in it. There's probably a standard recipe that the manufacturer uses and inserts the appropriate taste - peanut butter cups, peppermint patties, etc, at the request of their customers.
There are plenty of links for a coupon for a free pie, on the internet.