In a large pot, cook the lasagna noodles according to package directions.
While the noodles are cooking, combine the browned beef, sausage, tomatoes, spaghetti seasoning and other seasonings together in a large bowl.
In a separate bowl, combine the ricotta cheese, spinach and egg.
In the casserole dish, place the first layer of noodles, overlapping the edges of the noodles a little bit if necessary. Then, evenly spread half the meat mixture and top the meat with another layer of noodles.
Next, evenly spread the ricotta mixture over the noodle layer, then sprinkle 1/3 of the mozzarella cheese on top.
Add another layer of noodles, then top with the remaining meat mixture and 1/3 of the mozzarella cheese.
Top the lasagna with the remaining mozzarella cheese and sprinkle shredded parmesan cheese on top.
Lay a sheet of parchment paper on top of the lasagna to keep the cheese from sticking to the foil, then cover the entire dish tightly with foil. Place the casserole in the freezer until ready to eat.
Cooking instructions:
Transfer the lasagna to the refrigerator the day before cooking to thaw completely.
When ready to cook, preheat the oven to 325°. Keep the casserole covered and bake for 1 to 1 1/2 hours, removing foil and parchment paper for the last 30 minutes of cooking.
After removing the pan from the oven, let the lasagna set for 10-15 minutes before serving.