Preheat the oven to 375°F (190°C).
In a large skillet, cook the ground beef over medium heat until browned, approximately 5-7 minutes.
Drain any excess grease from the skillet. Add marinara sauce and Italian seasoning to the beef and stir to combine.
Cook the tortellini according to package instructions, usually about 3-4 minutes, until al dente.
Fold the cooked tortellini into the beef and marinara mixture, ensuring they are well coated.
In a bowl, combine ricotta cheese, half of the mozzarella, and half of the Parmesan cheese; mix until creamy.
Spread half of the beef and tortellini mixture in a greased baking dish, followed by layers of the ricotta mix and remaining beef mixture.
Top the last layer with the remaining mozzarella and Parmesan cheese.
Cover with foil and bake for 25 minutes. Remove the foil and bake an additional 10-15 minutes, until cheese is bubbly and golden.
Let the bake sit for 5 minutes before serving, garnished with fresh basil if desired.