In large bowl, mix 1 cup of the flour, 1 cup cornmeal, the sugar, salt and yeast. In 1-quart saucepan, heat water and 1/4 cup butter until hot (120°F to 130°F). Add hot liquid to flour mixture; beat with electric mixer on low speed until moistened, scraping bowl frequently. Beat on medium speed 2 minutes, scraping bowl frequently. With spoon, stir in 1/2 to 1 cup of the flour until dough pulls away from side of bowl.