In a large mixing bowl, combine the warm water and yeast and allow to rest until foamy.
Add 3 1/2 cups of flour, the sugar, salt, and butter.
Beat with a mixer on low speed for 1 minute. Scrape the sides and beat on medium speed for 1 minute.
Stir in enough remaining flour to make the dough easy to handle.
Turn the dough onto a lightly flour surface. Knead about 10 minutes, or until smooth and elastic.
Place in a greased bowl and turn to coat dough.
Cover and allow to rise in a warm place until doubled - about 1 hour. The dough is ready if an indentation remains when poked.
When the dough has risen, grease 2 loaf pans and set aside,
Punch the dough down and divide in two. Working on a floured surface and with one half at a time, flatten the dough down, with your hands or a rolling pin, into a 18x9 inch rectangle. Roll the dough up tightly, pinch the ends to seal, and place in a loaf pan.
Cover and allow to rise in a warm place until doubled - 35-50 more minutes.
When the dough is almost ready, heat the oven to 425°.
Bake 25-30 minutes, or until the bread is golden brown and the bottom sizzles when touched with a wet finger.
Allow to rest for a few minutes in the loaf pans then remove and cool on wire racks.Brush with butter if desired.
Notes:
Make Ahead: It works great to make these ahead of time and freeze them for toast.