01 - Cook elbow macaroni according to package directions until al dente. Drain well and rinse under cold running water to halt cooking. Transfer to a large bowl and let cool completely.
02 - In a separate medium bowl, whisk together mayonnaise, sour cream, Dijon mustard, apple cider vinegar, sugar, salt, black pepper, and smoked paprika until smooth and thoroughly combined.
03 - Add cooled macaroni, diced celery, red bell pepper, red onion, and shredded carrots to the bowl with the dressing. Fold gently with a spatula until all ingredients are evenly coated.
04 - If using, fold in sweet pickle relish and chopped fresh parsley until distributed throughout the salad.
05 - Cover the bowl tightly with plastic wrap or a lid. Refrigerate for at least 1 hour to allow flavors to meld. Before serving, give the salad a quick stir and adjust seasonings if desired. Serve cold.