First, in a large skillet, sauté the onion and garlic in the olive oil for two minutes over medium high heat.
Now, add the ground beef and brown it while breaking the meat into small pieces. Drain and access fat (if needed) and season the meat mixture with salt, pepper, garlic powder and Italian seasoning.
Next, stir in the tomato sauce and let it simmer for about 5 minutes.
Now, line a 9x13" baking dish with an about ¼ of the sauce.
Then, place the ravioli down side by side over the sauce until it covers it all.
Next, sprinkle the top with half of the shredded mozzarella and parmesan cheese.
Then add another layer of sauce and ravioli.
For the final layer, add a little more sauce and the rest of the shredded mozzarella cheese.
Finally, bake at 350° for about 30 minutes or until the cheese is melted and the sides are hot and bubbly.
Garnish with parsley (optional), serve warm and enjoy.