I have a question about the recipe "Chrissy Teigen’s French Toast Casserole with Salted Frosted Flakes" from Genius Recipes. Can you substitute French bread with challah or brioche?
I do think it will work. French toast casserole are very forgiving. There's a lot of liquid in this version, so I would suggest drying out your challah or brioche in the oven or countertop before assembling. I do that anyway with all breads for this type of casserole. Report back with your results if you can.