In a large bowl, combine the grated coconut, grated sweet potato, sugar, water, and salt. Mix well until the ingredients are evenly distributed.
If using banana leaves, cut them into squares and lightly steam or blanch them to make them pliable.
Spoon a portion of the mixture onto the center of each banana leaf or parchment paper square.
Fold the edges of the leaf or paper to form a secure package, wrapping it tightly to seal the mixture inside.
Steam the wrapped koni in a steamer or a large pot with a steaming rack for about 45-60 minutes, or until the sweet potato is fully cooked and tender. If using parchment paper, you may need to adjust the cooking time slightly.
Allow the koni to cool slightly before unwrapping.
Enjoy your meal!