Combine the warm water, molasses, and active dry yeast in a glass measuring cup or small bowl. Stir with whisk until yeast dissolves, and then let stand about 5-10 min. until yeast proofs.
Add the oil to the yeast mixture. In a large bowl, combine the cornmeal, salt, and about 2 cups of the flour. Add the yeast mixture, and stir to combine. Add flour a little at a time until the dough forms a ball and pulls away from the sides of the bowl.
Knead dough on a lightly floured surface, adding flour if needed, until dough is smooth and elastic (8-10 min.). Put dough in an oiled bowl (or spray with cooking spray), and turn to coat. Cover with plastic wrap or damp towel, and let rise in a warm place for 1 hour or until doubled.
When doubled in size, deflate dough, and shape into loaf. Place loaf in a greased 9 x 5 in. loaf pan, cover, and let rise until it's about 1/2 in. above the pan. Bake at 375 for about 25 minutes. Remove from pan and let cool. For a softer crust, brush top lightly with melted butter after baking.