Cook meatballs in a large skillet over medium-high heat for 5 minutes turning occasionally until browned on all sides.
Place meatballs in a 4 quart slow cooker, reserving drippings in skillet. Reduce heat to low; add oil to skillet. Whisk in flour and next 4 ingredients until smooth. Increase heat to medium; cook, whisking constantly, 1 minute. Gradually whisk in chicken broth and wine. Cook, whisking frequently, 4 minutes or until slightly thickened. Pour gravy over meatballs. Cover and cook 3 hours on LOW.
Remove meatballs from slow cooker with a slotted spoon, and place in a serving bowl. Add sour cream, parsley, and if desired, jelly to gravy, whisking until blended. Pour over meatballs. Serve over hot cooked noodles; garnish, if desired.