I had the same problem with the little magic line pan and it wasn't done in the middle with the nutty bread. So I also have a great pan by Amco that comes with a top to slide on the top. So I doubled the recipe, added 1 tsp xanthan gum and subbed 1/2 of the arrowroot powder with Pamela's pancake baking mix, baked at 350 with top on most of the way (just left a tiny bit open for steam to escape) for 30 minutes and then took top off for last 20 minutes. Total bake time was around 45-50 minutes. It came out great. Totally done in the middle and the top was not all cracked and brown. (I also added hemp seeds to increase protein, but that is besides the point. It worked great for me,good luck!