8 ears corn, silks removed but husks left on, soaked in cold water for at least 10 minutes
1/4 cup mayonnaise
1/8 teaspoon cayenne, or to taste
3/4 cup shredded cotija or feta
Accompaniment: lime wedges
Soak corn in husks in cold water 10 minutes. Drain corn and grill on a rack set 5 to 6 inches over glowing coals until husks are charred, about 10 minutes. Shuck corn and grill until kernels are browned in spots, about 10 minutes.
While corn is grilling, in a small bowl whisk together mayonnaise and cayenne.
Brush mayonnaise mixture onto hot corn and sprinkle with cojita.
Serve corn on the cob with lime wedges.