Crumble the beef and sausage into a large frying pan and cook over medium heat, breaking apart any large pieces, for 10 minutes, or until cooked through. Drain off the fat and stir in the marinara sauce. Spoon a little of the sauce into a 9-by-13-inch baking dish and spread it around to cover the bottom. (This is just to keep the pasta from sticking to the bottom of the dish.)
Arrange a layer of uncooked noodles over the sauce and top with 1/3 of the remaining sauce. Spread one half of the cottage cheese over the sauce and top with 1/3 of the mozzarella. Add another layer of noodles, sauce, cottage cheese, and mozzarella. Add a final layer of noodles, sauce, and mozzarella cheese. Cover the pan with aluminum foil coated with cooking spray and refrigerate for at least 4 hours or overnight.
Preheat the oven to 350 degrees. Bake the lasagna for 1 hour or until heated through (insert a knife blade in the center, remove, and then touch the blade to test how hot the lasagna is in the center). Remove the aluminum foil and bake for 30 minutes, or until the cheese is lightly browned. Serve immediately.