Over a medium-hot grill roast the corn until the husks are charred, about 10 minutes if done over the stove grill. Turn the husk occasionally to uniformly char the husk while not burning the kernels underneath it. Set the charred husk aside to cool, then shuck them and cut off the corns from the cob.
Meanwhile, in a small bowl mix together the mayonnaise, sour cream, hot sauce, lime juice, chicken stock, salt, pepper, and sugar. Mix well and set aside
When ready to eat, in a large skillet add the corn and the mayonnaise mixture and sauté over medium-low heat until warm. Pour into a bowl, and garnish with cilantro, cotija cheese, and chili powder.