In a mixing bowl, combine 2 cups flour, sugar, yeast and salt. In a saucepan, heat water and butter to 120-130 degrees. Add to dry ingredients; beat until blended. Add egg; beat on low speed for 30 seconds, then on high for 3 minutes. Stir in remaining flour (batter will be stiff). Do not knead. Cover and let rise in a warm place until doubled, about 30 minutes.