01 -
Preheat oven to 175°C (350°F). Grease a 9-by-13-inch baking dish and set aside.
02 -
In a large skillet over medium heat, cook ground beef with diced onion until beef is browned and onion is softened. Drain excess fat. Season with garlic powder, salt, and black pepper.
03 -
Add tomato sauce, cream of mushroom soup, and sour cream to the skillet with the beef mixture. Stir well and heat through.
04 -
Spread half of the cooked pasta in the prepared baking dish. Top with half of the beef sauce mixture, then sprinkle with half of the shredded cheddar cheese. Repeat layers with remaining pasta, beef mixture, and cheddar cheese.
05 -
Evenly sprinkle shredded mozzarella cheese over the top layer.
06 -
Cover with foil and bake for 20 minutes. Remove foil and bake an additional 10 minutes until cheese is melted and bubbly.
07 -
Remove from oven, garnish with chopped parsley if desired, and serve warm.