Brown the ground beef in a large skillet over medium heat, breaking it up as it cooks. Add the onion and garlic and cook until the onion softens.
Transfer the beef mixture to the slow cooker. Add the mushrooms, beef broth, Worcestershire sauce, paprika, salt, and pepper. Stir to combine.
Cover and cook on low for 6 to 7 hours until the mushrooms are tender and the flavors have blended.
Stir in the cream cheese until melted, then stir in the sour cream. Keep the slow cooker on warm while you prepare the noodles.
Cook the egg noodles in a large pot of boiling water according to package directions. Drain and divide among bowls.
Spoon the beef stroganoff over the noodles and sprinkle with fresh parsley before serving.