Preheat the oven to 350°F (175°C).
Cook the egg noodles according to package directions. Drain and set aside.
In a large skillet over medium heat, warm olive oil and sauté the chopped onion until translucent.
Add the ground beef, garlic powder, salt, and pepper. Cook until beef is browned and fully cooked. Drain excess fat.
Stir in the tomato sauce and simmer for 5 minutes.
In a large bowl, combine the cooked noodles and sour cream. Mix well.
Layer half of the noodle mixture in a 9x13-inch baking dish. Top with half of the beef mixture and 1 cup of cheddar cheese.
Repeat layers with remaining noodles, beef, and cheese.
Bake uncovered for 20–25 minutes until heated through and cheese is melted.
Garnish with fresh parsley if desired before serving.