In a large skillet over medium-high heat, brown the ground beef until no longer pink, approximately 7 minutes. Drain excess fat.
Stir in the marinara sauce, water, oregano, and garlic powder. Bring the mixture to a gentle simmer.
Add the frozen ravioli to the skillet and stir to ensure they are mostly submerged in the sauce.
Reduce heat to medium-low, cover, and cook for 10 minutes until ravioli are tender.
Uncover and sprinkle mozzarella and Parmesan cheese evenly over the top.
Replace the lid and cook for 2 to 3 minutes until the cheese is fully melted.
Remove from heat, garnish with fresh parsley, and let rest for 5 minutes before serving.