Toss the coconut and salt together in a small bowl; set aside.
Blend the pandan leaves with 3/4 cup water in a blender or food processor until smooth; strain through a piece of cheesecloth. You should get about 1/2 cup pandan juice.
Bring 3 cups water and the tapioca pearls to a boil in a sauce pan; cook at a boil until the pearls are translucent and soft, about 10 minutes. Stir the sugar and tapioca flour into the mixture until the sugar is completely dissolved; add the pandan juice and stir until you have a thick batter. Remove from heat and pour into foil cups.
Bring a couple inches of water to boil in a large pot. Place a few of the cups at a time in a steamer insert and place over the boiling water. Steam until the cakes are cooked through, 10 to 15 minutes. Top the cakes with the coconut to serve.