Wow, great idea, and the manufacturer actually explains it for DIY-ers! It doesn't really heat a whole house, but for a small hut, it could work on cold spring/fall evenings when you don't want to start the wood stove.
Campfire Brownies in an orange: at least 1 orange per camper, Brownie or cake mix, 1 sharp knife, Sturdy soup spoons, Heavy foil wrap. Notes: For brownie mix you will get approx. 8 – 10 desserts. Cake mix will yield approx. 12 – 16 desserts.