Add a cup of sugar to a well-beaten egg. Combine 2 cups flour & 2 teaspoons baking powder, and add to the sugar mxture. While doing this, alternate between adding 1 cup of milk, beating well, and ending with the flour mixture. Stir in 1/4 cup melted butter & 2 and 1/2 teaspoons vanilla. Spoon onto a greased muffin pan. Sprinkle with sugar & cinnamon.