Cook the elbow macaroni according to package instructions until al dente. Drain and rinse under cold water to cool. Set aside.

In a large mixing bowl, combine the mayonnaise, Dijon mustard, apple cider vinegar, sugar, salt, and black pepper. Whisk until smooth and well combined.

Add the cooled macaroni, celery, red bell pepper, red onion, peas, and chopped hard-boiled eggs to the bowl. Gently fold the ingredients together until everything is evenly coated with the dressing.

Stir in the chopped parsley for added freshness.

Cover the bowl with plastic wrap and refrigerate for at least 1 hour to allow the flavors to meld. Serve chilled.