Step 1: Prepare the Pasta and Form the Crust

1. Cook the Spaghetti: Bring a large pot of salted water to a rolling boil. Add the spaghetti and cook according to package directions until it is al dente. It’s very important not to overcook the pasta, as it will continue to cook in the oven. Aim for the lower end of the recommended cooking time.
2. Drain and Mix: Drain the spaghetti well and return it to the hot pot. Add the melted butter and toss to coat every strand. This prevents it from sticking.
3. Bind the Crust: In a small bowl, whisk together the 2 beaten eggs, ⅔ cup of grated Parmesan cheese, and ½ teaspoon of black pepper. Pour this mixture over the buttered spaghetti and use tongs to toss everything together until the spaghetti is thoroughly and evenly coated. The heat from the pasta will help temper the eggs slightly.
4. Form the Crust: Generously grease a 9-inch deep-dish pie plate with butter or non-stick cooking spray. Transfer the spaghetti mixture into the prepared plate. Using the back of a spoon or your hands, press the spaghetti firmly against the bottom and up the sides of the plate to form a thick, even crust. Set aside while you prepare the fillings.

Step 2: Cook the Hearty Meat Sauce

1. Brown the Beef: In a large skillet or Dutch oven, cook the ground beef over medium-high heat, breaking it apart with a spoon, until it is no longer pink.
2. Sauté Aromatics: Drain off any excess grease from the skillet. Add the chopped yellow onion to the beef and cook for 4-5 minutes, until it has softened and become translucent. Add the minced garlic and cook for another minute until fragrant.
3. Simmer the Sauce: Pour the entire jar of marinara sauce into the skillet. Add the dried oregano, dried basil, salt, and optional red pepper flakes. Stir well to combine. Bring the sauce to a gentle simmer, then reduce the heat to low, cover, and let it simmer for at least 15-20 minutes to allow the flavors to meld together. Taste and adjust seasoning if necessary.

Step 3: Mix the Creamy Cheese Filling

1. Combine Ingredients: While the sauce is simmering, prepare the cheese filling. In a medium bowl, combine the 15 ounces of ricotta cheese, 1 cup of shredded mozzarella, and the chopped fresh parsley.
2. Season: Season the mixture with a pinch of salt and pepper and stir until it’s well combined and creamy.

Step 4: Assemble and Bake Your Masterpiece

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. First Layer – Cheese: Spread the ricotta cheese mixture evenly over the bottom of the spaghetti crust. Use an offset spatula or the back of a spoon to create a smooth, level layer.
3. Second Layer – Sauce: Carefully spoon the meat sauce over the ricotta layer, spreading it out to the edges of the pie.
4. Final Layer – Mozzarella: Sprinkle the remaining 1 ½ cups of shredded mozzarella cheese evenly over the top of the meat sauce.
5. Bake to Perfection: Place the pie plate on a baking sheet to catch any potential drips. Bake in the preheated oven for 25-30 minutes, or until the cheese is completely melted, bubbly, and starting to turn golden brown on top.
6. Rest and Set: This is a crucial step! Remove the Spaghetti Pie from the oven and let it rest on a wire rack for at least 10-15 minutes before slicing. This allows the pie to set, ensuring you get clean, beautiful slices that hold their shape.