Preheat the oven to 350°F (175°C).

In a mixing bowl, combine cooked spaghetti, beaten eggs, Parmesan cheese, and olive oil. Mix well.

Press the spaghetti mixture into the bottom and up the sides of a greased 9-inch pie dish to form a crust.

In a skillet, combine cooked ground beef, marinara sauce, Italian seasoning, salt, and black pepper. Heat until warmed through.

In a separate bowl, mix ricotta cheese and half of the mozzarella cheese.

Spread the ricotta mixture over the spaghetti crust.

Layer the beef mixture on top of the ricotta.

Sprinkle the remaining mozzarella cheese on top.

Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden.

Allow to cool for a few minutes before slicing and serving.