Preheat the grill to medium-high heat.
When the grill is hot, place corn directly on on the grates. Flip occasionally until all sides are lightly charred (about 5-10 minutes).
While the corn is cooking mix together the Mexican crema, mayo, lime zest, lime juice and chili powder in a small bowl. Set aside.
Once corn has cooked, brush the crema sauce all over the top. Sprinkle with cotija cheese and cilantro. Add salt and pepper (plus more chili powder) to taste.