Bring a large pot of salted water to a boil. Cook the pasta ravioli according to package instructions. Drain and set aside.

In a skillet, heat olive oil over medium heat. Add garlic and onion, and cook until softened. Add ground beef, salt, black pepper, dried basil, dried oregano, and crushed red pepper flakes. Cook until the beef is browned and cooked through. Stir in tomato sauce and simmer for 5 minutes.

In a mixing bowl, combine ricotta cheese, Parmesan cheese, beaten egg, and fresh parsley. Mix well.

Preheat the oven to 375°F (190°C). Spread a thin layer of the meat sauce in the bottom of a baking dish. Place a layer of cooked pasta ravioli on top. Spoon a layer of the cheese mixture over the ravioli. Repeat the layers until all the ingredients are used, ending with a layer of meat sauce. Sprinkle mozzarella cheese on top.

Cover the baking dish with foil and bake for 20 minutes. Remove the foil and bake for an additional 10 minutes, or until the cheese is melted and bubbly.

Garnish with fresh basil leaves, if desired. Serve hot.