Preheat oven to 375°F (190°C) and grease a 9x13-inch baking dish.
Brown ground beef with onion and garlic in a skillet, then drain excess grease.
Stir marinara sauce and Italian seasoning into the meat mixture and simmer 3–4 minutes.
In a bowl, mix cream cheese, ricotta, and sour cream until smooth.
Spread a thin layer of meat sauce in the baking dish.
Layer half the frozen ravioli, half the cream mixture, and half the mozzarella.
Repeat layers and finish with remaining meat sauce and parmesan on top.
Cover with foil and bake 25 minutes, uncover and bake 10 more minutes until bubbly.
Let rest 5–10 minutes before serving and garnish with parsley.