Bring a large pot of water to a boil over high heat. Carefully add the fresh corn kernels and cook for 5–7 minutes, or until tender and bright yellow. Drain and rinse under cold water.

In a mixing bowl, combine the cooled corn, diced cucumber, halved cherry tomatoes, and chopped red onion. Toss gently with a spatula.

In a separate bowl, whisk together mayonnaise, sour cream, lime juice, chili powder, salt, and pepper until smooth. Adjust seasoning as needed.

Pour the dressing over the salad mixture and gently fold until well-coated.

Sprinkle crumbled feta and cilantro on top. Serve immediately or chill for 20 minutes before serving.