Start by bringing a large pot of salted water to a rolling boil. Add elbow macaroni and cook for 7-8 minutes until al dente. Drain and rinse under cold water.

In a large mixing bowl, combine mayonnaise, sour cream, apple cider vinegar, Dijon mustard, sugar, and a pinch of salt and black pepper. Whisk until smooth.

Gently add the cooled macaroni into the dressing and fold in diced red onion, diced celery, diced red bell pepper, and chopped fresh parsley. Toss until evenly coated.

Cover with plastic wrap and refrigerate for at least 1 hour, preferably 2 hours, to allow flavors to meld.