Hi i'm new to this forum i just thought of an idea earlier today. So basically i thought of an oven where instead of putting stone around the outside you put steel around the out side and a blaze rod in the middle. This does not deafet the purpas of coal becasue you can still make tourches and you have to go to the nether to get as blaze rod. I uploaded an image
Edit: It does not require coal or any resource to use it each time.