Preheat your oven to 375°F (190°C).
In a large skillet, brown the ground beef over medium heat until fully cooked, about 6-8 minutes. Drain excess fat.
Stir in marinara sauce and Italian seasoning to the skillet; simmer for 2-3 minutes to combine flavors.
Cook the tortellini according to the package directions until al dente; drain and set aside.
Combine the cooked tortellini, beef mixture, and half of the mozzarella and Parmesan cheese in a mixing bowl; stir gently.
Pour the mixture into a greased 9x13 inch baking dish, spreading it evenly.
Top with the remaining mozzarella and Parmesan cheeses, and season with salt and pepper to taste.
Bake in the preheated oven for 25-30 minutes or until the cheese is melted and bubbly.
Let the bake cool for 5 minutes before serving. Garnish with fresh basil, if desired.