Preheat oven to 350°F. Grease a 3-quart baking dish and set aside.
In a large pot set over medium heat, brown ground beef and garlic until meat is no longer pink, breaking it up and stirring frequently. Drain fat. Season meat with garlic powder, dried basil, dried parsley, dried oregano, dried thyme, crushed red pepper flakes (if desired), and salt and freshly ground black pepper, to taste.
Stir pasta sauce into cooked ground beef. Pour frozen tortellini into a colander and run under warm water for a minute to slightly thaw. Drain and stir tortellini into meat sauce.
Remove pot from heat and stir in half of the grated mozzarella. Transfer tortellini/meat sauce into the prepared baking dish. Top with remaining grated mozzarella and sprinkle with grated Parmesan. Cover with foil and bake for 20 minutes. Remove foil and bake for about 20 minutes more, or until hot and bubbly.