Preheat oven to 350 degrees. Spray a 13x9 baking dish with non-stick spray.
Heat a large skillet over medium heat and add the ground beef and onion. Brown the beef, crumbling it as it cooks. Drain the grease from the pan.
Add the marinara sauce and garlic and simmer for 5 minutes, stirring often, over low heat.
While sauce is simmering, mix ricotta, egg, Parmesan, parsley, garlic powder, and onion powder in a small bowl.
Spoon 1/3 of the meat mixture into the prepared baking dish and spread across the bottom.
Top with a single layer of ravioli, ½ of the ricotta mixture, and 1/3 of the sauce. Repeat the layers, ending in marinara sauce.
Sprinkle the top with the shredded mozzarella. Cover tightly with foil and bake for 40 minutes. Remove cover and bake for 10 minutes more.
Remove from the oven and sprinkle with minced parsley.
Let set for 10 minutes before cutting and serving.