Pat the shrimp gently with paper towels to absorb any excess moisture. Set aside.
In a medium bowl, mix the coconut water, sugar, caramel, and fish sauce until well-combined. (Andrea recommends tasting it to make sure it has a nice balance of sugar and fish sauce. If necessary, add a little more of either.)
Heat the coconut oil in a large skillet with the shallots and garlic over medium heat. Cook the shallots and garlic, stirring frequently, until they're translucent. Turn off heat and let cool a few minutes.
Add the coconut water to the skillet and turn the heat up to medium-high until the coconut water starts to boil. Let the mixture reduce at a steady simmer, adjusting the heat as necessary so it stays there, until it's reduced to about 1/2 cup (125ml). It will take 10 to 12 minutes. Add the shrimp and cook, stirring constantly, until the shrimp are just cooked through and the sauce is reduced to a loose, yet thickened syrup. If you think the shrimp are cooking too fast before the sauce is properly reduced, you can remove them with a slotted spoon, let the sauce reduce, then add them back.
Turn off the heat and stir in the scallions as well as a good amount of black pepper. Let the mixture sit for a minute or so before serving, stirring the shrimp so it gets coated in the sauce. If the juices get too thick, you can dribble in a little more coconut water to loosen things up.