Add the palm sugar and water to a pan and cook to make caramel. Do not use chopsticks or a spoon to stir, as this can cause the sugar to crystallize and harden.

Once the sugar turns a nice brown color, add the coconut milk and stir well. Turn off the heat and let the mixture cool to about 86–104°F (30–40°C). Do not let the coconut milk boil, as this can cause the cake to separate after baking.

When the palm sugar and coconut milk mixture is warm, sift in the tapioca starch and rice flour. Stir in one direction until smooth.

Crack the eggs into a bowl and gently whisk until the yolks and whites are combined. Strain the eggs, then add them and the vanilla to the batter. Mix well, then add the vegetable oil and stir until fully combined. Sift the batter 2–3 times for a smooth texture, then let it rest for 15–20 minutes.

Preheat the oven and the baking pan at 340°F (170°C) for 10 minutes. Remove the pan, brush the inside with butter, then return it to the oven to heat for another 5 minutes at 340°F (170°C). At this point, add the baking powder to the batter and mix well until fully combined.

Remove the hot pan from the oven and quickly and gently pour the batter into the pan. Bake at 340°F (170°C) for 20 minutes, then lower the temperature to 320°F (160°C) and bake for another 25–30 minutes. Check the cake by inserting a toothpick into the center—if it comes out clean, the cake is done. Invert the pan and slightly open the oven door to let the cake cool, then remove it from the pan.

Once cooled, cut the cake into small, pretty pieces. The delicious aroma and flavor will make everyone want to try it!