In large bowl, mix whole wheat flour, 1/4 cup granulated sugar, the salt and yeast. In 1-quart saucepan, heat water and 1/4 cup butter until very warm (120°F to 130°F). Add warm liquid and egg to flour mixture; beat with electric mixer on low speed until moistened, scraping bowl frequently. Beat on medium speed 3 minutes, scraping bowl frequently. Stir in enough all-purpose flour until dough pulls cleanly away from side of bowl.