Add salt to 8 quarts of water in a large pot and bring to a boil. Add garlic and boil 1 minute. Remove garlic and reserve. Add corn to water. Allow to return to a rolling boil, then turn off heat. After 10 minutes, remove corn from water, place on a platter and cover.
While corn is cooking, add mayonnaise, lime juice, chipotle with adobo, creme freche, molasses, and garlic to a blender, and puree until smooth. Pour into a bowl and mix in 3/4 cup cotija cheese and 1/4 cup cilantro. Cover and refrigerate until ready to use.
Mix together remaining cheese and cilantro. Cover and refrigerate.
To serve, place corn on a hot grill, occasionally rotating ears until corn is slightly charred all around. Remove from grill. Brush all around with mayonnaise mixture, sprinkle with reserved cheese mixture and serve