Step 1

Preheat the oven to 350 degrees F.

Step 2

In a large pot, bring salted water to a boil.

Step 3

Cook the egg noodles in the boiling water to al dente according to the package directions.

Step 4

Drain the water from the pasta and set the pasta aside.

Step 5

In a large skillet over medium heat, cook the beef while crumbling until no longer pink, about 7-10 minutes. Season with garlic salt.

Step 6

Drain the excess fat from the cooked meat, if needed.

Step 7

Stir the marinara sauce into the cooked meat and simmer for 10 minutes.

Step 8

In a medium bowl, combine the sour cream, cream cheese, and onion. Be sure to mix well.

Step 9

In an ungreased 9x13-inch baking dish, arrange 1/2 of the cooked noodles.

Step 10

Pour the sauce mixture over the arranged noodles, then top the sauce with the sour cream mixture.

Step 11

Top the sour cream mixture with the remaining noodles and the grated cheese.

Step 12

Bake the casserole until the cheese is melted and bubbly, about 25-30 minutes.

Step 13

Serve.