Preheat griddle to low. Combine half of the flour, the salt, cornmeal, and yeast in a bowl with the butter. Stir the molasses and warm water together and beat into the flour mixture gradually. Add enough of the remaining flour, about 1/4 cup, to make a stiff dough and beat well. Stir in the remaining flour until the dough is no longer sticky. Turn out onto a floured board and knead until smooth, about 8 minutes.
Place the dough in a greased bowl and cover with plastic wrap. Let rise in a warm place until it doubles in size. Punch down to form an oblong ball. Roll out on a floured surface to form a rectangle, about 1/2 inch thick. Brush griddle with olive oil. Place dough on griddle and cook on each side 4 to 5 minutes.