Preheat oven to 350 degrees. Spray a 9x13 inch dish with cooking spray.
Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8-10 minutes or until al dente; drain.
In a large skillet over medium heat, brown the ground beef. Add the tomatoes with juice, salt and sugar to the beef. Simmer for 15 minutes.
In a medium bowl, combine the sour cream, cream cheese, and onion. Mix well.
In prepared dish, place half of the egg noodles, then all of the meat mixture, and then the cream mixture. Top with remaining noodles and sprinkle with the cheese. Bake at 350 degrees for 25 minutes.