Add water to a large pot and bring to a boil over medium-high heat. Salt the boiling water, then add the elbow macaroni. Stir briefly. Cook the pasta uncovered for the time indicated on the package plus an additional 2 minutes, until soft.

Drain the pasta and while it's still hot, mix in the apple cider vinegar. Toss to combine and allow it to cool. You can speed up the cooling process by placing it in the refrigerator.

In a medium bowl, whisk together mayonnaise, whole milk or half-and-half, grated onion, light brown sugar, black pepper, and kosher salt.

In a large bowl, combine the cooled pasta, grated carrot, and diced celery. Pour the dressing over the pasta mixture and toss until everything is evenly coated.

Refrigerate the salad for at least 1 hour to allow the flavors to meld. Stir well before serving. Adjust seasoning if needed.