Begin by bringing a large pot of salted water to a rolling boil. Add the rotini pasta and cook for 8-10 minutes, or until al dente. Drain the pasta in a colander and immediately rinse it under cold water to halt the cooking process.

While the pasta cools, take a large mixing bowl and prepare your vegetables. Add the corn kernels and toss in the halved cherry tomatoes. Finely chop the red onion and add it to the bowl, then crumble in the feta cheese and add fresh cilantro, mixing gently.

In a medium bowl, whisk together the mayonnaise and sour cream until smooth. Squeeze in the fresh lime juice, then sprinkle in the chili powder, garlic powder, salt, and pepper, whisking until well combined.

Add the cooled rotini pasta to the large bowl of vegetables. Pour the dressing over the pasta mix and gently toss everything together until thoroughly coated.

Cover the bowl with plastic wrap or a lid and refrigerate for at least 30 minutes to allow the flavors to meld together.

After chilling, gently stir the salad to recombine any settled ingredients. Taste and adjust seasoning as necessary, adding more salt, pepper, or lime juice to taste. Serve cold.