In a large pot, bring 8 cups water to a boil. Add sago, stirring to avoid clumping. Return to a boil, then reduce heat and cook for 10-15 mins or until sago becomes translucent, stirring regularly.
Drain and rinse sago with cold water to separate grains. Drain completely then add to 6 serving glasses, cover with cling wrap and refrigerate overnight to set. In a small pot, stir together palm sugar and 1 cup water. Bring to a boil, and simmer for 8-10 mins or until sugar has dissolved and has begun to thicken slightly. Refrigerate overnight.
Once ready to serve, top pudding with chilled coconut cream, palm sugar syrup and mango slices.