Sprinkle the cereal on the bottom of a greased 8" springform cake pan. Arrange the apple slices over the cereal and sprinkle them with the lemon rind, lemon juice and cinnamon. Combine the ricotta, sugar, egg white and whole egg and yogurt in a medium bowl, mixing with a spoon until smooth. Pour evenly over the apples. Bake in a preheated 350 degrees oven for 45 minutes. When cool, go around the circumference of the pan with a knife before removing the side.