Cook the elbow macaroni according to package instructions until al dente. Drain and rinse under cold water to cool. Set aside.
In a large mixing bowl, combine the corn, red bell pepper, red onion, and cilantro.
In a separate bowl, whisk together the mayonnaise, sour cream, lime juice, chili powder, garlic powder, salt, and pepper until smooth.
Add the cooked macaroni to the bowl with the vegetables. Pour the dressing over the pasta and mix until everything is well combined.
If using, gently fold in the crumbled feta cheese.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld.
Serve chilled and enjoy!