Step 1: Cook the rotini pasta according to package directions until al dente. Drain and rinse under cold water to cool.
Step 2: In a large bowl, combine the cooked pasta, diced ham, pineapple, red bell pepper, celery, and green onions.
Step 3: In a small bowl, whisk together mayonnaise, sour cream, apple cider vinegar, sugar, salt, and black pepper until smooth.
Step 4: Pour the dressing over the pasta mixture and toss gently until everything is evenly coated.
Step 5: Cover and refrigerate for at least 1 hour to allow flavors to meld before serving.