Make the Dressing

In a medium mixing bowl, whisk together:

2 cups half-and-half

2 cups mayonnaise

1 ½ tablespoons grated yellow onion

1 tablespoon dark brown sugar

1 teaspoon salt

2 teaspoons pepper

Whisk until smooth and creamy. Cover and refrigerate until ready to use.

Cook the Macaroni

Bring a large pot of salted water to a boil.

Add 1 pound elbow macaroni and cook 5 minutes longer than the package instructions—you want the pasta very soft and plump.

Drain the pasta well in a colander. Immediately return it to the warm pot and pour in ¼ cup apple cider vinegar. Stir thoroughly until the pasta absorbs the vinegar.

Cover the pot and let sit at room temperature for 20 minutes to cool slightly.

First Dressing Addition

After 20 minutes, add half of the prepared dressing to the pasta and stir to combine. Cover the pot again and let cool for another 20 minutes.

Final Mix-In

After the second cooling period, add:

Remaining half of the dressing

Sliced green onions

Chopped celery

Grated carrots

Mix well until everything is evenly coated. Taste and adjust seasoning with salt and pepper if needed.

Chill and Serve

Let the salad cool completely at room temperature (about 30 minutes), then transfer to a serving bowl. Cover with plastic wrap and refrigerate for at least 2 hours before serving. Stir again before serving.