Preheat oven to 200 degrees C. Lightly grease muffin tin or line with paper cases.
Mix together egg, egg whites and milk. Stir in coffee, water and vanilla.
In a large bowl, mix together flour, 3/4 of the sugar, baking powder and salt. Stir in liquid mixture. Mix together really well, until batter is thin and gooey like cake batter. Fill muffin cups 2/3 full. In a small bowl, stir together cinnamon and remaining sugar. Sprinkle cinnamon sugar over muffins.