Coconut filling - Add water, gula melaka and pandan leaves into a pot and stir mixture to boil at medium heat till gula melaka melted. Drop in white coconut and corn flour and turn to low heat. Continue to cook mixture for about 5 minutes until syrup almost dries up. Leave filling to cool.
Preheat oven at 170 deg C. Line 10 x 11 or 10 x 12 inch, lined baking tray with parchment paper .
In a large bowl, mix egg yolks, sugar and oil, stir well with a hand whisk. Combine coconut milk and pandan juice together and pour into egg mixture, stir well. Sift in cake flour and corn flour, mix well again.
Whisk egg whites till frothy, gradually add in the sugar in batches. Continue beating till egg whites are stiff but not dry.
Add ⅓ of the egg whites into the egg mixture, fold well with a rubber spatula. Then gently fold in the rest of egg whites till combined.
Pour batter into prepared tray and spread out with a rubber spatula. Gently tap the tray to release air bubbles. Bake in preheated oven and bake for about 18 minutes. Remove cake from pan, remove the parchment paper and leave to cool.
Whisk fresh topping cream to peak form and spread on to sponge cake，(not too thick), then the coconut filling on top. Gently roll up the sponge cake to make a Swiss roll and chill it for a few hours before serving.
Please keep in mind that all oven temperatures and baking time varies.For extracting the pandan juice, please refer hereYou may spread the remaining cocnut filling on bread for breakfast or snack.