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 cooked pasta, diced chicken, crumbled bacon, cherry tomatoes, chopped romaine, and shredded cheddar cheese.

In a separate bowl, whisk together the mayonnaise, sour cream, Dijon mustard, lemon juice, garlic powder, salt, and pepper until smooth.

Pour the dressing over the pasta mixture and toss gently until everything is well coated.

Cover the bowl and refrigerate for at least 30 minutes to allow the flavors to meld.

Before serving, give the salad a good stir and adjust seasoning if necessary.