Begin by bringing a large pot of salted water to a rolling boil. Add your spaghetti and cook according to the package directions, typically around 8-10 minutes, until it's al dente. Once done, drain the pasta in a colander and set it aside to cool slightly while you prepare the creamy sauce.

In a spacious mixing bowl, combine softened cream cheese, marinara sauce, garlic powder, Italian seasoning, salt, and pepper. Use a spatula to mix the ingredients together until the mixture is smooth and creamy without any lumps.

Carefully toss the cooked spaghetti into the cream cheese sauce, ensuring each noodle is coated in the rich mixture.

Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with non-stick spray or butter. Transfer the spaghetti mixture into the dish.

Sprinkle a generous layer of shredded mozzarella cheese evenly over the top followed by cheddar and finished with grated Parmesan cheese.

Place your casserole in the preheated oven and bake for 25-30 minutes until the cheese melts and turns a golden brown.

Once baked, carefully remove the casserole from the oven and let it cool for about 5-10 minutes. Garnish with chopped basil or parsley before serving.