Cook the rotini pasta according to package instructions until al dente. Drain and rinse under cold water to cool.
In a large mixing bowl, combine the cooled pasta, cherry tomatoes, cucumber, bell pepper, corn, red onion, and cheddar cheese.
In a separate bowl, whisk together the ranch dressing, garlic powder, black pepper, and salt until well combined.
Pour the dressing over the pasta and vegetable mixture. Toss gently until everything is evenly coated.
If desired, stir in the fresh parsley for added flavor and color.
Cover the salad and refrigerate for at least 30 minutes before serving to allow the flavors to meld.