Preheat your oven to 350°F (175°C).

In a large pot, bring salted water to a boil and cook spaghetti noodles until al dente (about 8-10 minutes). Drain and set aside.

In a large mixing bowl, combine cooked chicken, cream of mushroom soup, sour cream, garlic powder, onion powder, and salt and pepper. Stir until blended.

Gently fold the drained spaghetti into the creamy mixture until coated.

Pour the mixture into a greased casserole dish and spread evenly. Sprinkle cheddar cheese on top.

In a small bowl, mix breadcrumbs, grated Parmesan, and olive oil. Sprinkle over the cheese layer.

Bake for 25-30 minutes until bubbly and golden.

Let the casserole cool for 5-10 minutes before serving. Garnish with fresh parsley if desired.