After much research, and making of Apple Bakers, we decided to try them out before we put them out for sale to the general public. I actually had someone else bake some apples in them a few weeks ago with no problems, but I figure it is best to do your own testing.
I bought some Rambo Apples from Way Fruit Farm, cored them with a paring knife, placed them on the spikes. Then I slapped a TBS of butter on each one, dumped on some brown sugar, cinnamon and allspice, and a few cashews we had in the cupboard. Then I added a TBS of water to the baker and put it into the oven at 350 for about 40 minutes. Here are the pictures.
Here are the results: YUM!