Preheat oven to 350 degrees F. In a large pot of boiling salted water, cook noodles to desired doneness; drain and set aside. Coat a 9"x13" baking dish with cooking spray. Layer 4 noodles on bottom of prepared dish. Spread 1 can of apple pie filling on top,slicing any extra-thick apples.
Layer 4 noodles over the apples. In a large bowl,mix together the Cheddar cheese, ricotta cheese, egg and granulated sugar. Spread them evenly over the noodles and top with the remaining 4 noodles. Spoon remaining can of apple pie filling over noodles.
In a small bowl,crumble together the flour, cinnamon,margarine,brown sugar and quick oats. Sprinkle over the apple filling. Bake 45 minutes. Let stand 15 minutes then slice into serving-sized pieces and serve warm or cold. If desired, you can mix together 1 cup (1/2 pint) sour cream and 1/3 cup light or dark brown sugar and serve the lasagna with dollops of this topping for garnish.