Combine whole wheat flour, undissolved yeast, sugar and salt in a large bowl. Heat milk, water and butter until very warm (120° to 130°F). Add to flour mixture. Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add 1/4 cup all-purpose flour; beat 2 minutes at high speed. Stir in enough remaining all-purpose flour to make soft dough. Knead on lightly floured surface until smooth and elastic, about 8 to 10 minutes. Cover; let rest 10 minutes.
Divide dough into 12 equal pieces; shape into balls. Place in greased 8 or 9-inch round pan. Cover; let rise in warm, draft-free place until doubled in size, about 30 minutes.
Bake in preheated 375°F oven for 15 to 20 minutes or until done. Remove from pan; brush with additional melted butter, if desired. Serve warm.