My mother-in-law is gluten and lactose intolerant, so I thought I'd give this a shot on her last visit. Yum! Very cakelike, good nutty texture and taste from the beans. I think I would change it by adding a bit of vanilla, and using bittersweet chocolate, but otherwise it's great. I'm going to keep making it for myself even though she's gone home. :-)
Make sure the flour you use to dust the pan is gluten-free, or even better, use cocoa instead.