Beat together the eggs, cinnamon and clear vanilla. In separate bowl, mix together the flour and sugar (or Splenda). Stir in the buttermilk.
Add the egg mixture to the buttermilk or sour milk mixture; stir well. Pour into pie shell. Sprinkle with nutmeg. Bake at 450°F for 10 minutes. Reduce the heat and bake at 350°F for 30 minutes or until knife inserted near center comes out clean. Serve immediately or refrigerate.