I cut a hole through the wall, and look Honey, I found a oven!
Building up the hearth inside of the house . . . I was using a small propane burner to slowly dry it out . . . building up the chimney too!
I then covered it with 2 layers of alum foil, to keep the bricks form joining the concrete I was going to pour of it . . . for mass heat retention.
My Father had come over on Dec 1, to help me pour the concrete, it was a cold rainy day, he slipped on some wet grass on the side of the hill, and broke his leg in three places!

After the ER visit, my WONDERFUL Wife helped me mix the concrete and pour the top . . .
Doors on, hearth finished, thermocouple juction box in, damper/flue in . . .
Just needs a match, and then start getting dough ready!
The plans I drew up, my own design, feel free to use if you want to
A hot oven . . . this is 4.5" in to the brick!
It was alot of work . . . took longer than I planned!