Place the quartered new red potatoes in a large pot and cover with cold, salted water. Bring to a boil and cook for 15-20 minutes, or until potatoes are fork-tender. Drain immediately.

While the potatoes are cooking, prepare the dressing. In a medium bowl, whisk together the mayonnaise, apple cider vinegar, Dijon mustard, chopped dill, sugar, salt, and pepper until completely smooth and creamy.

Transfer the warm, drained potatoes to a large mixing bowl. While still warm, pour about half of the prepared dressing over the potatoes and gently toss to coat. The warmth helps the potatoes absorb the flavor.

Add the finely chopped celery, diced red onion, and chopped hard-boiled eggs to the bowl with the potatoes. Pour the remaining dressing over the mixture.

Gently fold all the ingredients together until evenly combined. Be careful not to mash the potatoes. Taste and adjust seasoning (salt/pepper) if necessary.

Cover the potato salad and refrigerate for at least 2 hours (preferably 4 hours) to allow the flavors to meld. Garnish with extra fresh dill before serving chilled.