Some years ago, before the advancement of electrical home appliances, most local delicacies were baked in a oven like this. Cleverly adapts what nature provides us, folks are able to serve many mouth watering kueh such as Akok, Nekbat, Kueh Bakar, Baulu, Penganan, Beker Nyior, among a few.
Today, we still can find people baking kueh by this way. With this method, mostly, people believe that the kueh will taste better. Probably "bau asap" linger well with the "bau Bahulu" or maybe also, a little bit hard work doing things the old way, put more value into the kueh, thus it will taste better, physcologically.
What ever it is, this is nature adaption at it's best.