Preheat oven to 450°.
To prepare potatoes, combine first 3 ingredients. Arrange evenly on a jelly-roll pan coated with cooking spray. Bake at 450° for 30 minutes or until tender. Let cool. Combine potatoes, onions, parsley, and bacon.
To prepare vinaigrette, combine vinegar and remaining ingredients in a jar. Cover tightly; shake vigorously. Add vinaigrette to potato mixture; toss well. Serve immediately.