Preheat oven to 350 degrees. Grease a 9” x 3” cake pan or deep dish pie pan with cooking spray or olive oil. (Spring form pan works best). You can also use a casserole dish. In a large pot of boiling salted water (about 2 teaspoons of salt), cook spaghetti noodles al dente (very firm to the touch). Drain pasta, reserving ½ cup pasta water. Do not rinse pasta. Set aside. In a skillet, over medium-high heat, sauté chopped onion and garlic in olive oil until soft and translucent. Add ground beef or turkey, Italian sausage, salt, pepper and crushed red pepper. Stir to incorporate and cook until browned. (Drain any excess grease.) Add marinara sauce and stir to combine. Cook for 5 minutes. Set aside to cool. In a large bowl, stir together the eggs, ricotta, ½ cup mozzarella, ½ cup Parmesan, and parsley. Add the cooked spaghetti and meat sauce, stirring gently to fully incorporate ingredients. Spoon mixture into prepared pan, gently pressing spaghetti into pan. Top with the remaining mozzarella and Parmesan cheese. Bake for about 25-30 minutes or until the cheese is bubbling and golden brown. Let sit for 5 minutes so spaghetti pie can set up. Spoon a couple of tablespoons of reserved marinara sauce onto plate. Slice spaghetti pie into wedges, place on top of the sauce. Spoon more sauce over top if desired. Sprinkle with Parmesan cheese and fresh parsley.