In a saucepan, add sugar, coconut, milk, and salt. Cook over medium heat until the sugar has fully dissolved.
Remove from heat and let it cool slightly.
In a large bowl, crack the eggs and lightly beat with a fork. Add the pandan extract (and vanilla, if using). Pour in the cooled coconut mixture and stir gently.
Sift in the tapioca starch and baking powder. Gently fold until just combined.
Sift the mixture into a separate bowl for a smooth batter. Add the neutral oil and gently mix.
Carefully remove the hot pan from the oven. Immediately pour in the batter. Bake for 45 minutes, or until the cake is set and slightly golden on top. Do not open the oven early.
Remove from the oven. Flip the pan over and let the cake cool for 1 hour on a wire rack.
Once cooled, remove the cake from the pan, slice into pieces, and enjoy your perfect pandan honeycomb cake!