Preheat your oven to 350°F (175°C).
Cook the egg noodles according to package instructions until al dente. Drain and set aside.
In a large skillet over medium heat, brown the ground beef and chopped onion until the beef is cooked through and the onion is translucent. Drain excess fat.
In a large bowl, combine the cream of mushroom soup, cream of chicken soup, sour cream, garlic powder, salt, black pepper, and paprika. Mix well until smooth.
Add the cooked egg noodles, ground beef mixture, shredded cheddar cheese, and frozen mixed vegetables to the bowl. Stir until all ingredients are well combined.
Transfer the mixture to a greased 9x13-inch baking dish, spreading it evenly.
Bake in the preheated oven for 25-30 minutes, until the casserole is bubbly and the top is lightly golden.
Remove from the oven and let it cool for a few minutes before serving.