Rinse corn on the cob to get rid of all the silk from the cobs. Set aside.
In a small bowl, melt the butter and set aside.
In a separate small bowl, squeeze the juice of the limes and set aside.
Combine the chili powder, cayenne pepper salt and pepper, mix well and place in a separate small bowl.
Shred the cotija cheese and place in a separate bowl.
Take a basting brush and baste a bit of butter on the ears of corn.
Generously sprinkle each cob with the dry spices of chili powder, cayenne pepper salt and pepper.
Place ears of corn on a grill and grill for about 15 minutes or until the kernels start to turn a light brown color.
When corn is done on the grill, take the basting brush and baste the lime juice on each ear, along with a bit more melted butter.
Top with cotija cheese and serve immediately.