While your grill preheats, combine the melted butter and mayonnaise in a small bowl, stirring until smooth and well incorporated. In a separate shallow dish, mix together the crumbled cotija cheese, ancho chili powder, and fresh cilantro. This ensures your toppings are ready to apply quickly once the corn comes off the heat while it's still warm.

Heat your grill to medium-high heat. Place the shucked and cleaned corn directly on the grates, turning occasionally to develop an even char on all sides, about 7-10 minutes total. I find that rotating the corn every 2-3 minutes gives you beautiful caramelized spots without burning any single side, and the slight char adds a smoky depth that's essential to this dish.

Remove the corn from the grill and immediately brush each ear generously with the butter-mayonnaise mixture from Step 1, coating all sides evenly. While the corn is still hot, roll or sprinkle the cheese mixture from Step 1 over each ear, pressing gently so it adheres to the butter layer. The residual heat will help everything stick and slightly warm the cheese and cilantro, releasing their flavors.

Transfer the finished corn to a serving platter and serve immediately with lime wedges on the side. Diners can squeeze fresh lime juice over their corn just before eating to brighten all the rich, creamy, and savory flavors.