Combine ground beef, egg, breadcrumbs, milk, parsley, salt, poultry seasoning, and pepper in a bowl.

Shape mixture into 24 meatballs.

Brown meatballs in a skillet over medium heat, draining excess fat.

Add beef broth, mushrooms, and onion to the skillet.

Simmer covered for 30 minutes.

In a separate bowl, mix sour cream, flour, and caraway seed.

Add sour cream mixture to the simmering meatballs and broth.

Cook, stirring occasionally, until the sauce thickens (about 8 minutes).

Sift flour and salt for spaetzle in a bowl.

Add eggs and milk to the flour and salt, and beat well.

Press spaetzle batter through a coarse-sieved colander into boiling salted water.

Cook spaetzle for 5 minutes, then drain.

Combine breadcrumbs, garlic powder, and melted butter.

Sprinkle spaetzle with the breadcrumb mixture.

Serve spaetzle on a platter with a well in the center.

Spoon meatballs and sauce into the center of the spaetzle.