Hello Stephanie,
I've been baking bread for some years using a cast iron Dutch oven, and I had the same problem with an underdone center. I finally started to turn the whole loaf out of the pot for the final 10-15 minutes, and that solved the underdone problem.
March 23, 2019 at 3:07pm
In reply to I just baked this in my Le Creuset cast iron lidded casserole d… by Stefanie_B (not verified)