Grease or spray with cooking spray a 9 x 13 or similar size foil pan or freezer safe ceramic baker.
In a large skillet over medium-high heat, brown ground beef, breaking into crumbles with spoon. Drain fat as needed. To the beef, add the garlic, Italian seasoning, onion powder and marinara sauce.. Stir to combine. Reduce heat to medium and continue to cook 5 minutes until heated thru and flavors are blended.
Spread 1/3 of meat mixture in the bottom of prepared pan. Top with 1/2 of the raviolis, laying out in a single layer. Top with another 1/3 of the meat mixture and one-half each of the mozzarella and parmesan cheeses. Repeat the layers of ravioli, then meat sauce, ending with the cheeses and parsley.
Cover pan with foil, sealing edges then wrap completely in plastic wrap. Freeze for up to 3 months.
Thawing and Baking
Thaw ravioli in covered pan overnight in the refrigerator.
Preheat oven to 350°F. Remove plastic wrap from fil pan, leaving foil top on. Bake on center rack of the oven for 30 minutes. Remove the foil top and bake for 10 minutes more until casserole is bubbling around the edges. Serve warm.
To Bake from Frozen
No need to thaw – remove plastic and place foil covered pan in a 350° F oven and bake for 1-1/2 to 2 hours, until heated thru. Remove foil and bake 20 to 30 minutes longer until cheese is melted and sauce is bubbling around the edges. Garnish with fresh parsley before serving.