In a small bowl, mix agar-agar powder with ½ cup water. Let it sit for 15 minutes.
Cut pandan leaves into small pieces. Blend with 3 cups water until roughly combined, then strain using cheesecloth to extract the juice.
Pour the pandan juice into a pot and bring to a gentle simmer. Stir the agar-agar mixture again, then add it in. Cook over low heat until fully dissolved (no more than 5 minutes).
Add sugar and stir until completely dissolved. Pour into molds or cups and let it set at room temperature for 30 minutes.
Make the coconut layer
Simmer coconut milk over low heat. Once it starts to bubble at the edges, stir in the agar-agar mixture. Cook until fully dissolved (no more than 5 minutes).
In a clean bowl, mix the second amount of agar-agar powder with ½ cup water. Let it sit for 15 minutes.
Add sugar and salt to the coconut milk and stir until dissolved. Remove from heat.
Once the pandan layer is slightly firm (it doesn't have to be completely set yet), gently spoon the coconut layer on top. Let it set at room temperature for another 30 minutes.
Slice and serve, or refrigerate until fully chilled before serving.
Notes
Use the nutrition card in this recipe as a guideline.