
Oven canning used to be popular around the turn of the 20th century, where it seemed a handy way to keep the house cooler (before air conditioning, better home insulation, etc) than water bath canning. Some found that their fruit and veggies canned held their shape better, even, when canned in the oven.
I’d imagine that if you’re reading this post you know someone who oven cans, OR you’ve seen those cutesy recipes where the baker is directed in baking mini pies or mini muffins in mason jars the oven. If you can bake in them, why couldn’t you can in them, is the thought.