In the bowl of a stand mixer, combine 2 cups flour, yeast, sugar, salt.
In a microwave safe bowl, heat the butter and water until it is very warm, but not hot (about 120-130°F). The butter does not have to be completely melted.
With the mixer on low speed with the paddle attachment, gradually beat the liquid into dry ingredients until just blended. Increase the speed to medium and beat for two minutes, scraping the sides of the bowl as necessary. Beat in the remaining flour to make a soft dough, scraping the sides of the bowl as needed.
Switch to the dough hook attachment and knead the bread for 5-7 minutes until the dough is smooth and elastic.
Turn the dough out onto a floured surface. Cut the dough in half; cover and let it rest for 20 minutes. Spray a large cookie sheet with non-stick spray and sprinkle with cornmeal (optional).
On a floured surface, roll one dough half into a 15x10-inch rectangle. Starting with the 15-inch side, tightly roll the dough jelly-roll style. Pinch the seam to seal. Repeat with the other half of the dough. Place the loaves, seam-side down on a cookie sheet and taper the ends. Brush with vegetable oil. Cover loosely with plastic wrap and refrigerate for 6 to 24 hours.
To bake, preheat oven to 425°F. Remove the loaves from the refrigerator, uncover and let stand 10 minutes. Cut 3-4 diagonal slashes on top of each loaf. Bake for 20 minutes.
In a small bowl, beat egg white with 1 tablespoon water. Remove loaves from the oven. Combine egg white and water. Brush with loaves with egg mixture. Return to the oven and bake for an additional 5 minutes.
Allow the bread to cool completely, then store in an airtight container.