In a small bowl, combine the first six ingredients; stir in apple and raisins. Combine the buttermilk, egg yolk, butter and vanilla; stir into dry ingredients. In a small bowl, beat egg white until soft peaks form; fold into batter. , Pour batter by heaping 1/4 cupfuls onto a hot greased griddle; turn when bubbles form on top. Cook until the second side is lightly browned., Meanwhile, in a small saucepan, combine the sugar, cornstarch and cider until smooth; add cinnamon stick. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Discard cinnamon stick. Stir nutmeg into syrup. Serve pancakes with warm syrup and, if desired, additional butter.