Preheat oven to 375°F. Spray 8x8-inch glass baking dish with cooking spray.
Cook beef and onion in large skillet until beef is crumbled and no longer pink, stirring occasionally. Stir in crushed tomatoes, Italian seasoning, sugar and garlic salt. Simmer 5 minutes, stirring occasionally.
Spread 1-1/4 cups meat sauce over bottom of dish. Place 2 noodles over meat sauce, top with half of the ricotta cheese, 3/4 cup mozzarella cheese and 1-1/4 cups meat sauce. Repeat layers. Top with remaining noodles, meat sauce and mozzarella cheese.
Spray underside of aluminum foil with cooking spray; cover dish tightly with foil. Bake 30 minutes. Remove foil; bake 15 minutes more or until cheese melts and sauce is bubbly. Let stand 10 minutes before serving.