• Step 1: Bring a large pot of salted water to a boil. Add the macaroni and cook according to package instructions, about 7-9 minutes, until al dente. Drain the macaroni and rinse with cold water to stop the cooking process.
• Step 2: In a large bowl, whisk together the mayonnaise, vinegar, Dijon mustard, sugar, salt, and black pepper until well combined.
• Step 3: Add the cooked and cooled macaroni, chopped hard-boiled eggs, diced celery, diced onion, and sweet pickle relish to the dressing. Stir gently until all the ingredients are evenly coated.
• Step 4: Cover the macaroni salad and refrigerate for at least 2 hours, or up to 3 days, to allow the flavors to meld.
• Step 5: Serve chilled, garnished with additional chopped hard-boiled eggs or fresh parsley, if desired.