Add the salt, cinnamon, and yeast to the flour and whisk well. Add the mashed banana and water and combine until all the flour is incorporated in the fluid.
Cover with plastic and let it sit on the counter 6, 8, 10 or 12 hours. I usually go to bed or go to work and bake it when I get home.
When it has doubled in size, preheat oven to 450 degrees.
Get two loaf pans ready or a Dutch oven. Line the loaf pan with parchment paper and dampen with water. Pour your dough into the loaf pan and gently smooth it out.
Cover the top of the loaf pan with another loaf pan so it has room to rise. Bake at 450 for 30 minutes. Remove the top loaf pan and bake 15 more minutes.
Remove from the oven and carefully pull it out of the loaf pan with the parchment paper. Let is cool completely before slicing. I store mine sliced in the freezer and get out 1 piece at a time to eat during the week. It warms well in the microwave 30 seconds.