Combine 1 cup flour, sugar, undissolved yeast, and salt in large mixer bowl. Heat water and butter until very warm (120° to 130°F), butter does not need to melt completely. Add to flour mixture. Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add egg and 1/2 cup flour; beat 2 minutes at high speed. Stir in remaining flour to make soft batter. Cover tightly with plastic wrap; refrigerate 2 to 24 hours.
Remove batter from refrigerator and let dough sit on counter for 20 minutes; if needed, stir in enough flour to make dough easy to handle. On lightly floured surface, roll to 12 x 8-inch rectangle. Beginning at short end, roll up tightly. Pinch seam and ends to seal. Place, seam side down, in greased 9 x 5-inch loaf pan. Cover; let rise in warm, draft-free place until nearly doubled in size, about 1 hour.
Bake at 350°F for 45 to 50 minutes or until done. Remove from pan; cool on wire rack.