In a small bowl, mix together coconut milk and fresh pandan juice with a spoon. Set aside. Combine the sifted flour, baking powder and white sugar in a bowl. Make a well; then add oil, egg yolks, vanilla extract, coconut milk and pandan juice mixture plus green colouring to the well. Set aside. Do not beat first. In a separate large mixing bowl, beat egg whites with high speed electric mixer. Gradually add the cream of tar-tar while beating until the egg whites turn very stiff and form soft peaks. Set aside. Using the same beaters, beat the egg yolk batter at a high speed until smooth and light. Gradually fold the egg yolk batter over the egg whites mixture by using rubber spatula. Do not stir. Pour the cake batter into a tube pan (do not grease the pan). Once done, shake the pan a little bit to release the air from the cake batter. Bake the cake in a preheated oven for 55-60 minutes until done. Do not open the oven until the cake is baked for minimum 40-45 minutes to avoid shrinking chiffon cake. Once done, invert the pan to cool and release the cake.