In large bowl, mix whole wheat flour, 1 cup of the all-purpose flour, the salt and yeast. In 1-quart saucepan, heat water and 6 tablespoons each of the honey and butter until very warm (120°F to 130°F). Beat warm liquid and egg into flour mixture with electric mixer on low speed until moistened, scraping bowl frequently. Beat on medium speed 3 minutes, scraping bowl frequently. Beat in remaining 1 to 1 1/2 cups all-purpose flour until soft, smooth dough forms (dough will be sticky). Cover; refrigerate 8 hours or overnight.