Cook the rotini pasta in salted water according to package directions until al dente. Drain and rinse under cold water to stop the cooking process, then let it cool completely.

In a large bowl, whisk together the ranch dressing, sour cream, milk, dill, garlic powder, black pepper, and salt until smooth.

Add the cooled pasta, crumbled bacon, cherry tomatoes, cheddar cheese, red onion, black olives, and cucumber to the bowl.

Toss everything gently until the pasta and vegetables are evenly coated with the dressing.

Taste and adjust seasoning if needed. Chill for at least 30 minutes before serving for the best flavor.