01 -
Preheat the oven to 350°F (175°C). Grease a 9 × 13-inch baking dish and set aside.
02 -
In a large skillet over medium heat, brown the ground beef with diced onion until the beef is fully cooked and the onion is softened. Drain excess grease.
03 -
Add garlic powder, salt, and black pepper to the beef mixture. Stir in tomato sauce, cream of mushroom soup, and sour cream. Combine thoroughly and heat through.
04 -
Spread half of the cooked pasta evenly in the bottom of the prepared baking dish. Layer with half of the beef mixture, then sprinkle with half of the shredded cheddar cheese.
05 -
Repeat with remaining pasta, beef mixture, and cheddar cheese, creating uniform layers.
06 -
Sprinkle mozzarella cheese evenly over the top layer.
07 -
Cover the dish with foil and bake for 20 minutes. Remove the foil and continue baking for another 10 minutes, until the cheese is fully melted and bubbling.
08 -
Remove from oven and optionally garnish with chopped fresh parsley. Serve warm.