01 - Bring a large pot of salted water to a boil. Add macaroni and cook until al dente, according to package instructions. Drain thoroughly and rinse under cold water to cool.
02 - In a large mixing bowl, combine cooled macaroni, celery, red bell pepper, red onion, carrots, and peas.
03 - In a separate small bowl, whisk together mayonnaise, sour cream, Dijon mustard, apple cider vinegar, sugar, salt, and black pepper until creamy and well blended.
04 - Pour the dressing over the macaroni and vegetable mixture. Gently fold until all ingredients are evenly coated.
05 - If desired, fold in chopped parsley and hard-boiled eggs for extra flavor and texture.
06 - Cover the bowl and refrigerate for at least 1 hour to allow flavors to develop. Stir gently before serving and adjust seasoning as needed.