Bring a large pot of salted water to a boil over medium-high heat. Once boiling, add fresh corn kernels and cook for 5 to 7 minutes, until tender yet still crisp. Using a slotted spoon, transfer the corn to a bowl of ice water to cool quickly, preventing further cooking. Drain and set aside.

In a large mixing bowl, combine the cooled corn with diced cucumber, halved cherry tomatoes, and finely chopped red onion. Gently fold the ingredients together, ensuring the vibrant colors are evenly distributed.

In a separate medium bowl, whisk together mayonnaise, sour cream, lime juice, chili powder, salt, and pepper until smooth and creamy. Taste the dressing and adjust seasoning as desired.

Pour the prepared dressing over the vegetable mixture in the large bowl. Using a spatula, gently toss everything together until all veggies are evenly coated with the dressing.

Before serving, sprinkle crumbled feta cheese and freshly chopped cilantro over the top of the salad for added flavor and texture.