Preheat your oven to 375°F (190°C) and lightly grease a 9x13 inch baking dish.

Boil the spaghetti in salted water until just al dente (about 1-2 minutes less than the package directions). Drain well.

In a large skillet over medium-high heat, brown the Italian sausage and ground beef, breaking it apart with a wooden spoon. Drain excess fat.

Pour the marinara sauce into the meat mixture and let it simmer on low for 5 minutes.

In a medium bowl, combine the ricotta, softened cream cheese, egg, minced garlic, and half of the parmesan cheese. Mix until smooth.

Assemble the casserole: Spread half of the cooked spaghetti evenly in the prepared baking dish. Spread the entire ricotta mixture over the pasta. Top with the remaining spaghetti.

Pour the meaty marinara sauce evenly over the top layer of spaghetti. Sprinkle the shredded mozzarella and remaining parmesan cheese over the sauce.

Bake uncovered for 30-35 minutes until the cheese is melted, bubbly, and slightly golden brown on the edges.

Let the casserole rest for 10-15 minutes before serving. Garnish with fresh chopped basil.