OK, I know this is late...LOL. But I just made yet another Bouche de Noel for my hubby to take to work. This is the second one since Christmas! When you bake it in a jelly roll pan-either a 15" or a 17" pan-make sure you line it with wax paper first. Then bake it. Flip it out onto a linen towel that has been dusted with powdered sugar, removed the wax paper and then fold thed short edge of the towel over the end and roll the cake up into a spiral. Let sit until cool-which takes several hours. Or you can do it the day before and fill the next day.
When you bake it in a jelly roll pan, and roll it up,the cake compresses so it doesn't get as thick as you think it will. It really does work well..and you are hailed as such a MARVELOUS baker!
PS the secret is not letting the cake cool before your roll it. You roll it while it is hot-right out of the oven.