We just got back from a stay there a week ago. We aren't gluten free, but we deal with several other allergies (milk, eggs, nuts). I dealt with 2 different managers during our stay and both were extremely nice and helpful. They will help you find something and prepare it carefully. I definitely saw gluten-free brownies and/or cookies.
I'm SPECULATING, but here are some ideas I think you might have success with. They have toss-to-order salads, so you could probably get one of those with the right ingredients and dressing. I'm sure they'd do a bunless burger and safely prepared fries for you. The honey-lime chicken sandwich is very good and might be safe without the bun. Same with the mahi fish sandwich. It wouldn't surprise me if they have access to gluten-free breads either, Udi's. We can't have those due to egg so I never asked to see if they carry them, but I would think the odds are good that either they keep a supply or that Chef Mickey's does and they can run over to that kitchen to get one.
We got an "allergy cupcake" from Chef Mickey's once. I asked the Contempo manager if it was possible to run over and get one. She said she could, but that she didn't offer them because she wasn't sure what was in them, but if I knew they were safe for DS she was happy to go get one. I know they're safe for my DS and I THINK they're top 8 free, but I'm not certain. If you dine at Chef Mickey's early in your stay you can ask the chef. Or maybe there's a way to contact them ahead of time to verify.
Never at at the pool snack bars.
