Preheat oven to 325F. Ina 4" full hotel pan add 1" of water and place in oven.
In a medium sauce pan, heat coconut milk and 1/2 cup of coconut palm sugar to a simmer and gently reduce by 1/3. Remove from heat and allow to cool slightly.
Grease and sugar 12-2" ramekins. Set aside.
In a small skillet add remaining 1 cup of sugar and 1/4 cup of water. Bring mixture to a boil, gently swirling to prevent burning. Once sugar has dissolved, pour equal amounts of caramel into each ramekin.
Whisk eggs together. Slowly pour in cooled coconut milk mixture a little at a time to ensure eggs do not cook. Then whisk in the lemon zest and vanilla.
Pour egg mixture evenly over caramel in the ramekins. Carefully place the custard filled ramekins in the water bath in the oven. Bake for 45-50 minutes or until the custard is set.
Once the custard is set, remove the ramekins from the water bath and refrigerate until cool. Run a knife around the outside edge of the custard. Place a plate over the top of the ramekin and flip over so the caramel oozes over the flan onto the plate.