the problem with whoopie pies, a plea for help

Something amazing happened.

For my darling Joe's birthday I gave him a beautiful French film poster. An enormous red one sheet, 63 " x 47", from a film by his favorite director. But that's not the amazing thing. I discovered that framing would cost at least twice what the poster did (and it wasn't cheap either), so I would have to save up for the framing; hanging the poster would be a gift for another occasion. That was last April.

Along comes our two year anniversary and I decide the occasion has arrived, but I still can't afford the price quoted me by the framers. I bring the poster to work and my boss suggests we ask the installers for advice. (I should mention that I work for an organization that houses one of the largest archives of film print materials in the world, if not THE largest--I assume the Library of Congress has a sizable stock--and the task of framing and hanging of said collection falls to this group of guys.) I show them my poster and ask for their advice. They confirm that the job costs about $600, and that I'll want it mounted on an archival-quality board. And then the amazing thing: they said they'd frame it for me, FOR FREE! They don't normally do this, it just so happened that they had a frame, a board, and plexiglass the size of my poster, all of which they planned to throw away because of a few scuffs.

I am so incredibly grateful, and so inexcusably clueless as to how to thank them that I baked them whoopie pies, which seemed like a good start, but proved problematic for storage and transportation. See, the top of a cake is the smoothest and most delicate. Most people have experienced what happens when icing a cake that hasn't adequately cooled: the fragile crust peels a bit, getting crumbs mixed in with the icing. Well imagine that the fragile upper crust, the delicate cake top serves as both the top and bottom of the dessert. Even when cooled to past the point of most normal cakes, the bottom of the pie (the lower upper crust) would stick to the plate, creating a big old hole, ruining the aesthetic.

I'll consider that perhaps this is a sign that whoopie pies are not the best way to thank my framer friends, nevertheless, this is a problem with whoopie pies that needs solving. Does anyone know how to prevent it? Do I need to wait longer? Freeze the cakes? Use a cooling rack? A little help would be greatly appreciated.