Brown the ground beef in a large oven-safe skillet over medium-high heat, breaking it up with a spoon, about 5-7 minutes. Drain excess fat and season with salt, pepper, garlic powder, and Italian seasoning.
Add the marinara sauce and beef broth to the skillet, stirring to combine with the seasoned beef.
Add the uncooked tortellini to the skillet and stir gently to coat with sauce. Bring to a simmer, then reduce heat to medium-low, cover, and cook for 8-10 minutes until tortellini is tender, stirring occasionally.
Preheat broiler to high. Sprinkle mozzarella and Parmesan cheese evenly over the top of the skillet.
Place skillet under the broiler for 2-3 minutes until cheese is melted, bubbly, and golden brown. Watch carefully to prevent burning.
Remove from oven, let cool for 5 minutes, and serve hot with additional Parmesan if desired.