Preheat the oven to 350ºF and spray a 9×13 casserole dish with cooking spray.
In a large skillet over medium heat, brown the ground beef and sausage. Drain off excess fat, then add minced garlic and spaghetti sauce. Simmer for 5 minutes.
In a large bowl, combine ricotta, 2 cups of mozzarella, eggs, ½ cup Parmesan, parsley, salt, and pepper. Mix well.
Spread ¾ cup of sauce on the bottom of the prepared baking pan. Lay 3 uncooked lasagna noodles over the sauce.
Top with ? of the cheese mixture and ¼ of the remaining sauce. Repeat layers twice.
Finish with a final layer of noodles, remaining sauce, 1 cup of mozzarella, and the rest of the Parmesan. Add water around the edges if using thick sauce.
Cover with aluminum foil sprayed with cooking spray (sprayed side down). Bake for 50 minutes. Uncover and bake for an additional 10 minutes.
Let stand for 10 minutes before serving.