To prepare the corn:
Carefully peel back the husks from the top of the corn to the stem, keeping the husks attached. Remove all of the silk and rewrap the husks around the corn. (You can tie the husks in place with string but this is not necessary).
Bring the water to a boil and add the corn and cook for approximately 10–15 minutes, until tender. Remove corn from the water, drain well and reserve.
To prepare the caramel:
Combine agave, molasses, maple syrup, condensed milk and butter in saucepan. Heat on medium-high heat until it comes to a boil, stirring well. Add salt.
Reduce heat to a simmer and cook 10–12 minutes. Remove and let cool.
Add a small amount of olive oil to a cast-iron skillet and heat.
Peel back the cornhusks from the boiled corn, making sure the ears are fully drained. Brown the corn ears a couple at a time in the oil, but not the husks.
Remove ears and place on plate. Drizzle corn with caramel and lightly sprinkle with sea salt to taste.