How is it possible for them not to be? Doesn’t the size make it so that low temperatures can’t reach the inside within a reasonable amount of time, and high ones burn the outside while the inside is still raw?
You concerned the worlds largest challah wasnt edible? the world largest burrito? bowl of clam chowder? please speel it out for those of us not quick on the uptake.
Are you talking about the Challah? I think most things can be cooked/baked properly if done right.
And if you meant challah, it is braided and long so I’d assume it’s not that hard to get the inside baked. You’d probably need to lower the temperature or even shut the oven heat completely intermittently to prevent the crust from becoming burnt while the inside stays “doughy”. Maybe not easy for a novice, but possible with the right oven and expertise.