Preheat your grill—whether gas or charcoal—to a steady 400°F. Once it reaches temperature, give the grates a good scrub with a grill brush to ensure a clean cooking surface.
While the grill heats up, prepare the creamy topping. In a mixing bowl, whisk together the mayonnaise, Mexican crema, chopped cilantro, minced garlic, chipotle pepper, lime zest, and lime juice. Give it a taste and season with salt if desired. Set the mixture aside for later use—it will be the flavorful coating that brings the whole dish together.
Place the corn directly onto the hot grill grates. Let each ear cook for about 3 minutes without moving, allowing the kernels to develop charred, golden spots. Turn the corn and continue grilling, rotating every few minutes, until all sides are beautifully blistered and cooked through. Once done, transfer the corn to a serving platter.
Generously coat each grilled cob with the prepared crema mixture, using either a basting brush or the back of a spoon to spread it evenly over the surface. Sprinkle each ear with crumbled cotija cheese, allowing it to cling to the creamy layer. If you like a bit more kick, dust with extra chipotle pepper. Serve the corn hot with lime wedges on the side for squeezing just before eating.