Step 1

Prep: Preheat oven to 350°F. Lightly grease a deep 13x9 inch pan. Cook spaghetti according to package directions; drain and put back in the pot. Drizzle with 1/2 tablespoon olive oil, cover with a lid and set aside.

Step 2

Make tomato sauce: While the spaghetti are cooking, in a skillet over medium heat, season ground beef with salt pepper and garlic powder, then cook until browned in remaining 1/2 tablespoon olive oil. Add onion and celery and cook until softened. Stir in Italian seasoning and tomato paste, then stir in diced tomatoes and simmer for 5 minutes. Set aside.

Step 3

Make cheese sauce: Combine all ingredients for cheese sauce until smooth. Set aside.

Step 4

Assemble: Place half of the cooked spaghetti in the prepared baking dish. Top with cheese sauce and remaining spaghetti. Spread spaghetti sauce on top and sprinkle with mozzarella cheese.

Step 5

Bake, uncovered, at 350°F for 35 ro 45 minutes, or until bubbly and cheese is melted. Makes 8 to 10 servings.