Place flour in the container of a food processor fitted with the steel blade. Add the salt and yeast and process for 5 seconds. With the machine running, add the sweetener, softened butter, and most of the milk through feed tube (you will need a little less milk if you are using a liquid sweetener). Process about 30 seconds, then remove the cover. The dough should be in a well-defined, barely sticky, easy-to-handle ball. If it is too dry, add milk 1 tablespoon at a time and process for 5 or 10 seconds after each addition. If it is too wet, which is unlikely, add a tablespoon or two of flour and process briefly. Knead for a minute or so by hand.
Use half the oil or melted butter to grease a large bowl. Shape the dough into a rough ball, place it in the bowl, and cover with plastic wrap or a damp towel. Let rise for at least 2 hours, until nearly doubled in bulk. Deflate the ball and shape it once again into a ball; let rest on a lightly floured surface for about 15 minutes, covered.
Using only enough flour to keep the dough from sticking to your hands or the work surface, flatten it into a rectangle, then shape it into a loaf. Use the remaining oil or butter to grease a 9 x 5-inch loaf pan (to the top of the pan). Place the loaf in the pan, flattening the top of it with the back of your hand. Cover and let rest for 1 hour, or until the top of the dough is nearly level with the top of the pan.
Preheat the oven to 350F. Brush the top fo the loaf lightly with water, and then place in the oven. Bake about 45 minutes (perhaps less -- 35 minutes?), or until the bottom of the loaf sounds hollow when you tap it (if will fall easily from the loaf pan) or the internal temperature reads about 200F. Remove loaf from pan and cool on a wire rack before slicing.