1.Remove the husks and silks from the corn. Place the ears directly on a grill over medium-high heat. Rotate the corn every 3 to 5 minutes. You want the kernels to be cooked on all sides and for light grill marks to form. The entire process should take about 15 minutes.
2.In a small bowl, stir together the mayonnaise and lime juice and zest. Spread the mayo mixture over the corn and sprinkle with the chili powder, Cotija, and cilantro. Season to taste with salt and serve with lime wedges for squeezing.