In a large bowl, combine the cooked rotini pasta, shredded chicken, cherry tomatoes, corn, red bell pepper, and red onion.
In a separate small bowl, whisk together the BBQ sauce, ranch dressing, garlic powder, salt, and pepper until well combined.
Pour the dressing over the pasta salad mixture and toss gently until everything is evenly coated.
If using, fold in the chopped cilantro for added flavor.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld together.
Serve chilled or at room temperature.