While searching for something completely unrelated, I ran into these instructions for building a medieval-style brick oven. It's clearly not meant to be super authentic, since it has materials such as a cheap plastic tarp.
What I found fascinating was the claim that "Our oven is based on one from the 12th century found in an excavation at York, England (i.e., Norman period), although it is similar to earlier Viking Age ones. The original was made out of wickerwork and completely covered inside and out with daub."
A wickerwork oven? I never would have thought of that, but protected by daub, properly dried and fired, there's no reason that wouldn't have worked.
Here's someone else who underestimated the power of wicker for baking.