Preheat your grill to medium-high heat (about 400 degrees Fahrenheit).
Place the shucked corn ears directly onto the grill grates. Grill for 10 to 15 minutes, turning every few minutes, until kernels are charred and tender.
While grilling, whisk together the crema, mayonnaise, and chili powder in a small bowl.
Remove the charred ears from the grill and immediately brush generously with the creamy sauce mixture.
Sprinkle the crumbled cotija cheese and chopped fresh cilantro evenly over each ear.
Serve warm with lime wedges for squeezing over the top.