Gather all your ingredients. Dice the onion and set it aside. Cook the spaghetti according to package instructions until al dente, then drain and set aside.
In a large skillet over medium heat, add the lean ground beef and diced onion. Cook until the beef is browned and the onion is translucent, about 5-7 minutes. Drain any excess fat.
To the beef mixture in the skillet, stir in the tomato sauce, tomato paste, Worcestershire sauce, sugar, dried oregano, garlic powder, and salt. Allow this mixture to simmer for about 10 minutes.
In a mixing bowl, combine the softened cream cheese, cottage cheese, sour cream, and sliced green onions. Mix until smooth and creamy.
In a large mixing bowl, combine the cooked spaghetti with the beef sauce mixture. Toss gently to ensure the spaghetti is well-coated.
Preheat your oven to 350°F (175°C). In the prepared baking dish, layer half of the spaghetti and beef mixture. Spread half of the creamy cheese mixture over the top. Repeat with remaining spaghetti and creamy mixture.
In a small bowl, mix the bread crumbs with the melted butter. Sprinkle the mixture evenly over the top of the casserole.
Place the casserole in the preheated oven and bake for 30-35 minutes or until the top is golden brown and the casserole is hot and bubbly.
Once baked, remove the casserole from the oven and let it cool for a few minutes. Slice and serve hot, garnished with additional green onions if desired.
