Heat oven to 400°F. Grease bottoms only of 24 miniature (1 3/4x1 inch) muffin cups with shortening or cooking spray, or line with paper baking cups.
In medium bowl, stir Bisquick mix, 1/4 cup sugar, the softened butter, milk, orange peel and egg until blended; beat vigorously with spoon 30 seconds. Divide batter evenly among muffin cups.
Bake 10 to 12 minutes or until light golden brown. In small bowl, stir together 2/3 cup sugar and the cinnamon. Immediately roll tops of muffins in melted butter, then in cinnamon-sugar mixture. Serve warm.