1Heat oven to 425°F. Grease bottom only of 12 regular-size muffin cups with shortening or cooking spray, or line with paper baking cups. In large bowl, stir together flour, 1/2 cup sugar and 1/4 teaspoon cinnamon.
2In small bowl, mix milk, 1/3 cup melted butter and the egg until well blended. Add to flour mixture; stir just until dry ingredients are moistened. (Batter will be slightly lumpy.) Divide batter evenly among muffin cups, filling each about 2/3 full.
3Bake 15 to 18 minutes or until golden brown. Meanwhile, in small bowl, mix 1/4 cup sugar and 1 teaspoon cinnamon.
4Remove muffins from muffin cups. Dip tops of warm muffins into 1/4 cup melted butter; dip into sugar-cinnamon mixture. Serve warm.