In a large pot boil the lasagna noodles (broken into 2- inch pieces) to al dente according to package directions. Drain and pour into a large mixing bowl. Cover noodles with lukewarm water. This will help prevent the noodles from sticking to each other. Set aside.
Preheat oven to 350° F.
In a large skillet, cook ground beef, sausage, onion and garlic over medium heat until browned. Drain off any excess fat and return to the pan.
Stir in the pasta sauce, Italian seasoning, salt, and pepper. Bring to a simmer and let cook for 10 minutes
While the sauce is simmering, in a separate bowl, mix together the ricotta cheese, thawed and drained spinach, and some salt and pepper to taste. Set aside.
Once done cooking, pour the meat sauce into the large bowl with the cooked pasta and mix together. To that mixture, add 1 cup mozzarella cheese, and 1 cup parmesan cheese and combine.
Lightly spray a 13 x 18 inch sheet pan (a half sheet pan) with non-stick cooking spray.
Pour all the lasagna noodles, sauce and cheese mixture onto the baking sheet and spread out evenly.
Next, places dollops of the ricotta mixture over the top of the noodle mixture. It will not fully cover it, just put spoonfuls around the pan. Then sprinkle on the remaining grated mozzarella cheese and parmesan cheese.
Bake for 35-40 minutes or until the cheese is golden brown and bubbly. Let the lasagna cool for 10 minutes before serving.