In the bowl of a stand mixer or a large bowl, combine the flour and salt.
In a small saucepan, mix together 2 tablespoons of the butter with the milk and bring to a simmer. Add the 1/2 cup of cornmeal and cook, stirring, for about 1 minute. Remove from the heat and let cool slightly.
Add the cornmeal mush to the bowl of flour and mix to combine well.
In a small cup, combine the warm water, molasses, and yeast. Pour the liquid into the flour mixture and beat until it comes together in a smooth, non-sticky dough. This will take about 10 minutes and is much easier to do in a stand mixer than by hand. If you feel that the dough is too sticky after 5 minutes, add a few teaspoons of flour.
Place the dough in a lightly greased bowl and cover with plastic wrap. Let it rise in a warm place until it has doubled in size, about 1 1/2 hours. Use the "finger poke" test to see if it has risen enough. (Press a finger about an inch into the dough. If the imprint of your finger stays, the dough is ready. If the dough springs back and fills in the hole slightly, it needs to keep rising.)
Take the dough out and press it into a rectangle, no thicker than 1 inch and no longer than 9 inches. Fold the dough in thirds lengthwise and pinch the seam closed. Place the shaped loaf in a greased 9 x 5-inch loaf pan and cover with plastic wrap. Let it rise until doubled in size.
Once the dough has risen, melt the remaining 2 tablespoons of butter and brush it over the surface of the loaf. Sprinkle with the remaining 2 tablespoons of cornmeal.
Bake the loaf in a 350° F oven for 40 to 45 minutes. The crust should be golden brown. Let the loaf cool for at least 15 minutes in the pan, then turn it out onto a rack to finish cooling.