Cook ziti pasta according to package directions. Once cooked, drain and set aside.

While pasta is cooking, heat a large skillet with olive oil over medium high heat. Saute garlic and onions for 2 minutes. Add ground beef and sausage; cook until browned. Drain excess fat and return to skillet.

Add marinara sauce, Italian seasoning, salt, and red pepper flakes to the skillet. Simmer on low until noodles are ready. Mix half of the meat sauce with cooked noodles; reserve the rest for layering.

In a small bowl, combine 1 cup shredded mozzarella, ricotta cheese, 1/4 cup grated parmesan, 2 tablespoons parsley, pepper, and eggs. Mix well.

Assemble in a 13x9 dish: pour half of meat-covered noodles, dollop half of cheese mixture, sprinkle with 1/2 cup mozzarella, and add half of remaining meat sauce. Repeat layers and top with remaining mozzarella and parmesan.

Bake uncovered at 375°F for 20-25 minutes until bubbly and cheese is melted. Garnish with remaining parsley and serve hot.