Preheat oven to 350 degrees. In a mixing bowl whisk together flour, baking soda, salt, cinnamon and nutmeg, set aside. In a large bowl, using an electric mixer, stir together granulated sugar, light-brown sugar, eggs, vegetable oil, applesauce, vanilla extract and maple flavor on low speed for 2 minutes. Stir in dry ingredients and mix just until incorporated. Stir in grated apples. Pour mixture into a buttered 15x10 inch jellyroll pan. Bake 22-25 minutes until golden brown and toothpick inserted into center comes out clean. Allow to cool to lukewarm then frost with Maple Cream Cheese Glaze. Sprinkle with optional nuts. Cut into bars. Store in an airtight container.
Maple Cream Cheese Glaze
In a mixing bowl, using an electric mixer, whip together cream cheese, butter, maple flavor and salt until smooth. Stir in powdered sugar and milk and mix until well blended and smooth.