In a large, non-metal mixing bowl combine 5 cups of the flour, 2 1/2 cups warm water, the starter and honey. Cover with plastic wrap or a damp towel and rest at room temperature for 12 hours.
Preheat the oven to 400 degrees F.
Stir in the oil, salt and baking powder, mixing well. Stir in 2 to 2 1/2 cups flour to make a soft dough. Turn the dough onto a floured surface and continue working in the flour until the dough is stiff enough to knead. Knead the dough until smooth and elastic, about 5 minutes.
Divide the dough in half and roll each into a 10-inch round loaf.
Melt 3 tablespoons of the butter in a 10-inch cast-iron skillet. Sprinkle 2 tablespoons of the cornmeal in the skillet. Place one loaf in the skillet and turn to coat both sides with the butter and cornmeal. Repeat for the remaining butter, cornmeal and dough. Using a sharp knife or razor, cut an "X" into the top of the loaves. Bake until cooked through, 35 to 45 minutes.
Serve warm with butter and honey.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.