Step 1: Cook the rotini pasta according to package directions until al dente. Drain thoroughly, then rinse with cold water to stop the cooking process and cool the pasta. Set aside to drain completely.
Step 2: In a large mixing bowl, combine the cooled pasta, shredded cooked chicken, crumbled bacon, halved cherry tomatoes, finely diced red onion, finely diced celery, and chopped fresh parsley.
Step 3: In a separate small bowl, prepare the dressing. Whisk together the mayonnaise, sour cream, apple cider vinegar, Dijon mustard, garlic powder, and onion powder until smooth. Season the dressing with salt and black pepper to taste, adjusting to your preference.
Step 4: Pour the prepared dressing over the pasta and vegetable mixture in the large bowl. Gently toss all the ingredients until everything is thoroughly coated with the creamy dressing.
Step 5: Cover the bowl and refrigerate the Sandwich Pasta Salad for at least 1 hour before serving. This allows the flavors to meld and deepen. Stir well before serving and enjoy!