Combine the beef, 1/2 cup coconut, cilantro, egg, lime juice, Worcestershire sauce, 1 tablespoon cream of coconut, soy sauce, and 1 1/2 teaspoons salt in a bowl until well mixed. Form into 4 patties, and set aside.
Stir together the mayonnaise with 2 teaspoons of cream of coconut and 1 tablespoon of cilantro; set aside. Heat the vegetable oil in a skillet over medium heat. Stir in 1 cup of coconut and 1/2 teaspoon salt. Cook and stir until the coconut has turned golden brown. Drain on a paper towel-lined plate and set aside.
Preheat an outdoor grill for medium-high heat, and lightly oil grate.
Cook the burgers on the preheated grill to your desired degree of doneness, about 4 minutes per side for medium-well. Spread both cut sides of the hamburger buns with the cilantro mayonnaise. Place the cooked burgers on the bottom buns, sprinkle with the toasted coconut, and serve.