Heat a gas or charcoal grill to 400F. Clean the grates once it has heated.
Whisk together the sauce: In a bowl, whisk together the crema, mayonnaise, cilantro, garlic, chipotle pepper, lime zest, and lime juice. Taste and season the mixture with salt if needed. (Crema has a little salt already, so add extra-judiciously.) Set aside.
Grill the corn: Place the husked corn directly onto grill grates. Grill the corn for about 3 minutes, undisturbed, or until kernels begin to turn golden brown and look charred. Turn over and repeat. When all sides are browned, remove from the grill onto a plate.
Top the corn with sauce and cheese: Using a brush or a spoon, coat each ear of corn with the cream mixture. Sprinkle with crumbled cojita cheese. Sprinkle with additional chipotle pepper, if desired. Serve immediately with extra lime wedges.