Preheat a gas or charcoal grill to medium-high heat, around 400-450°F.
Place the ears of corn directly on the preheated grill grates. Cook for 10-15 minutes, turning occasionally, until the kernels are tender and lightly charred in spots.
While the corn cooks, prepare the sauce by whisking together the mayonnaise, Mexican crema, crumbled cotija cheese, and 1 teaspoon of chili powder in a medium bowl until well combined.
Carefully remove the hot corn from the grill. Using a pastry brush or a spoon, generously coat each ear of corn with the prepared crema sauce.
Sprinkle the coated corn with additional crumbled cotija cheese, a light dusting of chili powder, and the chopped cilantro. Serve immediately with lime wedges on the side for squeezing over the top.