Preheat your oven to 375°F (190°C) and grease a 9x13 inch baking dish.
In a large skillet over medium heat, brown the ground beef until fully cooked, about 5-7 minutes. Drain any excess grease.
Add minced garlic to the skillet and sauté for an additional minute until fragrant.
Pour in the crushed tomatoes, oregano, basil, salt, and pepper. Stir and let simmer for about 5 minutes to meld the flavors.
In a large bowl, combine the cooked tortellini with the tomato-beef sauce. Mix well until the tortellini is evenly coated.
In a separate bowl, fold together ricotta cheese, half of the mozzarella, and half of the Parmesan cheese. Stir until well combined.
In the greased baking dish, spread half of the tortellini mixture in an even layer. Spoon dollops of the ricotta mixture on top, then add the remaining tortellini on top of that.
Sprinkle the remaining mozzarella and Parmesan cheese over the top.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 10-15 minutes, or until the cheese is bubbly and golden.
Once baked, let it cool for 5 minutes, then garnish with fresh basil leaves before serving.
Notes
Let the dish cool for a few minutes before serving.