Combine 1 cup flour, sugar, undissolved yeast and salt in a large bowl. Heat water, milk and butter until very warm (120° to 130°F). Gradually add to flour mixture. Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add egg and 1 cup flour; beat 2 minutes at high speed. Stir in enough remaining flour to make stiff batter.
Spoon into 18 greased or paper lined 2-1/2 inch muffin pan cups. (Muffin cups should be half full). Cover; let rise in warm, draft-free place until doubled in size, about 30 minutes. Sprinkle with Walnut Topping.
Bake at 375°F for 25 minutes or until done. Remove from pan; cool on wire rack. Drizzle with Powdered Sugar Glaze, if desired.
Walnut Topping: Combine brown sugar, flour, walnuts, butter and cinnamon. Stir to blend.
Powdered Sugar Glaze: Stir together powdered sugar and enough milk to reach desired consistency.