In bowl, beat egg with juice, oil and vanilla. Stir in flour, sugars, baking powder, and salt just until flour is moistened. Batter will be a little lumpy. Stir in nuts and chopped apple. Fill greased muffin tins or paper muffin cups about 2/3 full. Sprinkle with cinnamon sugar. Bake at 400° for 20 minutes or until golden brown.
*To make cinnamon sugar, blend about 1 1/2 teaspoons of cinnamon with 1/4 cup of granulated sugar.