Step 1: Cook the Pasta

1. Bring a large pot of salted water to a boil. Cook spaghetti until just al dente (about 1–2 minutes less than package directions).
2. Drain and toss with butter, beaten eggs, and Parmesan cheese. Set aside.

Step 2: Prepare the Meat Sauce

1. In a large skillet over medium heat, cook ground beef (or sausage) until browned. Drain excess fat if needed.
2. Add onion and garlic, cooking for 2–3 minutes until softened.
3. Stir in marinara sauce, diced tomatoes, Italian seasoning, salt, pepper, and red pepper flakes (if using). Simmer for 10 minutes.

Step 3: Assemble the Baked Spaghetti

1. Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish.
2. Spread half of the spaghetti mixture into the dish.
3. Layer with half of the meat sauce and then half of the ricotta mixture.
4. Repeat layers: remaining spaghetti, meat sauce, and ricotta mixture.
5. Sprinkle mozzarella and Parmesan on top.

Step 4: Bake & Serve

1. Cover with foil and bake for 25 minutes.
2. Remove foil and bake for another 10–15 minutes, until cheese is bubbly and golden.
3. Let sit for 5–10 minutes before slicing. Garnish with fresh parsley and serve!