Preheat oven to 350. Spray a 13 x 9 baking dish with cooking spray. In a large bowl whisk together flour, whole wheat flour, cinnamon, pumpkin pie spice, baking powder, baking soda, and salt. In a medium bowl whisk together pumpkin puree, applesauce, eggs, oil, SweetN Low®, and vanilla. Stir wet ingredients into dry ingredients until smooth, and spread batter evenly in baking dish. Bake until a toothpick inserted in the center comes out clean, about 20 minutes. Let cool completely on a rack. While cake cools, in a food processor combine cream cheese, yogurt, cornstarch, SweetN Low®, and vanilla. Pulse until smooth and creamy.
Frost cooled cake with cream cheese frosting. If desired, sprinkle with cinnamon before serving.