Heat olive oil over medium-high heat in a large skillet. Add onion and cook until translucent, about 5 minutes. Add garlic and cook for 1 minute. Add ground beef and cook until browned. Drain excess fat.
Stir in marinara sauce, diced tomatoes, oregano, basil, salt, and pepper. Simmer for 10 minutes.
In a medium bowl, mix ricotta cheese, cottage cheese, and sour cream until blended.
Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking dish.
Layer meat sauce, ravioli, cheese mixture, and meat sauce in the baking dish. Top with mozzarella, cheddar, and Parmesan.
Cover with foil and bake for 30 minutes. Remove foil and bake for an additional 15-20 minutes until cheese is melted and bubbly.
Let rest for 5-10 minutes. Garnish with parsley and serve.