How can you bake if you don’t have an oven? You make one, yourself. It is easier to show you how it has been done, than to describe the steps. There are numerous variations and alterations to the original idea, but that doesn’t matter. The main thing is you need a fireproof box, that can set on or above a heat source (wood, charcoal, gas or electric burner), and has a rack to hold baking items above that heat source. It needs a cover that fits tightly enough to stay on. Wooden blocks, fastened to the top and to the cover, will make it easier to open and close the oven while it is hot. Punch holes in the bottom to allow the heat to enter the oven and, at the same time, prevent flames from entering. (Some people cut a round hole in the bottom and then punch holes in the cut-out piece. They modify the cut circle with a wire handle, and use it to cover the hole as needed to control the temperature.)
Maybe you are wondering how you can tell the temperature of the oven. Old-timers, who didn’t have thermometers, used the terms “slow,” “medium,” and “hot” when describing the correct temperature. If I may use the same terms, there is a simple way to judge the temperature. If you put your hand inside, just above the rack (don’t touch the hot rack!), and can hold it there three (3) seconds before you have to jerk it out, it is a “slow” oven. If you can hold your hand there for two (2) seconds, it is a medium oven. And finally, if you can hold it there for only one (1) second, you have a hot oven.
Almost everything you bake will require a medium oven. Breads, cakes and casseroles are typical. Cookies and quick breads (muffins and doughs that contain baking soda) usually require a hot oven. It will take some practice to get it perfect every time, but your family will probably enjoy your efforts. If you try this, please send me pictures of your oven and your baked goods. I will enjoy them, and be glad to post them for all to see.