Preheat oven to 325 F.
Brush the bottom only of a cake pan with butter and place in the oven.
In the bowl of an electric mixer, combine coconut cream, salt, pandan paste, sugar and oil. Mix until thoroughly combined.
In a small bowl, crack the eggs. With a pair of scissors, cut the egg yolks. This is so less air will be whipped into the eggs. If there is too much air, the honeycomb texture will not result.
In another small bowl, combine the tapioca starch and the rice flour.
Add the eggs and half of the tapioca mixture to the electric mixer. Beat well until thoroughly combined.
Add the remaining tapioca mixture and beat until thoroughly combined.
Add cream of tartar and baking soda. Beat until well blended.
Pass batter through a sieve to get rid of any tapioca starch clumps.
Remove warm cake pan from the oven.
Transfer to prepared cake pan. Drop the cake pan on the counter a few times, to remove any air.
Transfer to oven and bake for 45 minutes.
Hang cake upside down to cool for 1 hour. I hope it works for you.
Slice and serve.