If grilling, preheat the grill. Place the corn directly on the grill and cook turning every 5 minutes, until all sides are cooked and corn is tender.
If using an oven, preheat the broiler on low. Place the corn underneath the broiler and cook turning every 5 minutes, until all sides are cooked and corn is tender.
Brush or spread the mayo onto the corn, sprinkle with the spices and cilantro. Season with salt and pepper. Cut the corn in half to portion.