Cook the Corn: Prepare fresh corn by grilling or boiling for 5–7 minutes, then cut kernels off the cob. For frozen corn, cook per instructions. In a skillet, heat olive oil, add corn, salt, pepper, and chili powder, sauté for 5 minutes until lightly charred. Let cool.

Make the Dressing: In a bowl, whisk together mayonnaise, sour cream, and lime juice until smooth. Set aside.

Combine the Ingredients: In a mixing bowl, combine cooled corn, cotija cheese, cilantro, and avocado if desired. Drizzle dressing over and toss gently.

Serve: Transfer to a serving dish and garnish with extra cotija cheese and cilantro. Enjoy immediately or chill for 30 minutes to flavor enhance.