Begin by boiling a large pot of salted water over high heat. Add Ditalini pasta and cook until al dente, about 8-10 minutes. Drain and rinse with cold water. Set aside to fully drain.

In a large mixing bowl, combine the cooled Ditalini pasta with the coleslaw mix, chopped sweet onion, diced celery, sliced cucumbers, chopped green pepper, and water chestnuts if using. Gently fold the ingredients together.

In a separate bowl, whisk together mayonnaise, granulated sugar, apple cider vinegar, salt, and black pepper until smooth. Adjust seasoning to taste.

Pour the dressing over the salad mixture and gently mix until all ingredients are coated.

Cover tightly with plastic wrap or transfer to an airtight container. Refrigerate for at least 4-6 hours to chill and allow flavors to meld.

After chilling, stir gently and transfer to a serving bowl. Enjoy your Coleslaw Pasta Salad cold.