Preheat oven to 350 degrees F. Prepare a large baking sheet lined with aluminum foil and sprayed with nonstick cooking spray. In a large bowl, combine all ingredients and mix well with your hands. Shape into about 30 (1-inch) meatballs. Arrange meatballs on baking sheet. Bake 20 to 25 minutes, or until cooked through.
Reduce heat to medium-low. Add cooked meatballs to mushroom broth and stir until heated through. Remove from heat and stir in sour cream. Season with salt and pepper.
For serving:
Meanwhile, bring a medium pot of water to a boil. Add pasta and cook al dente, according to package instructions, usually 7-8 minutes. Drain.
Add pasta to skillet with meatballs, tossing to combine. Warm briefly over low heat to blend flavors. Garnish with chopped parsley and serve immediately.