Preheat Oven:

• Preheat your oven to 350°F (175°C).

• Lightly grease a 9×13-inch baking dish.

Cook the Spaghetti:

• Bring a large pot of salted water to a boil.

• Cook spaghetti until al dente according to package directions.

• Drain and set aside.

Cook the Meat Sauce:

• In a large skillet, heat olive oil over medium heat.

• Add ground beef or sausage and cook until browned.

• Drain any excess fat.

• Stir in marinara sauce, garlic powder, salt, and pepper. Simmer for 5–10 minutes.

Make the Creamy Pasta Base:

• In a large bowl, combine hot cooked spaghetti with softened cream cheese and sour cream (if using).

• Mix until noodles are evenly coated and creamy.

Assemble the Casserole:

• Spread the creamy spaghetti mixture in the bottom of the prepared baking dish.

• Top with the meat sauce.

• Sprinkle mozzarella and Parmesan cheese evenly over the top.

Bake:

• Bake uncovered for 20–25 minutes, or until bubbly and golden on top.

Serve:

• Garnish with fresh parsley if desired.

• Serve hot with garlic bread or a crisp green salad.