Preheat the grill to medium-high heat. Place the corn on the grill and cook for about 10-15 minutes, turning occasionally, until the corn is charred and cooked through.

In a bowl, mix together the mayonnaise, cotija cheese, chili powder, lime juice, and salt until well combined.

Once the corn is grilled, remove it from the grill and brush the mayonnaise mixture generously over each ear of corn. Sprinkle with additional cotija cheese and chili powder if desired.