Creating the Baked Cream Cheese Spaghetti Casserole is straightforward when you follow these simple steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Cook Spaghetti: In a large pot of salted boiling water, cook the spaghetti according to the package directions until al dente. Drain and set aside.
3. Sauté Aromatics: In a large skillet over medium heat, heat the olive oil. Add the diced onion and minced garlic, sautéing until the onion becomes translucent.
4. Cook Meat: Add the ground beef or turkey to the skillet. Cook until browned and no longer pink, typically about 5-7 minutes.
5. Add Tomato Products: Stir in the tomato sauce, diced tomatoes, Italian seasoning, salt, and black pepper. Reduce heat and simmer for 10 minutes to meld the flavors.
6. Incorporate Cream Cheese: Add the softened cream cheese to the meat and sauce mixture. Stir until the cream cheese is completely melted and well incorporated.
7. Combine with Pasta: Add the cooked spaghetti to the skillet, tossing it until everything is well combined.
8. Transfer to Baking Dish: Pour the mixture into a greased 9×13-inch baking dish, spreading it evenly.
9. Add Cheese: Sprinkle the shredded mozzarella and grated Parmesan cheese evenly over the top.
10. Bake: Place in the preheated oven and bake for 25-30 minutes, or until the cheese is bubbling and slightly golden.
11. Cool and Serve: Remove from the oven and let it cool for 5-10 minutes before serving. Garnish with fresh parsley if desired.

By following these steps, you can effortlessly create this incredible casserole.