Preheat oven at 160°C / 320°F and line 2pcs x 21cm x25cm baking pan with parchment paper. Set aside.
Making the meringue
Separate egg whites and yolks. Set aside yolks for later use. In a mixing bowl, beat the egg whites using a hand mixer until frothy. Tip in cream of tartar and beat again for 3 – 4 minutes. Add sugar gradually or in 3 batches while beating in medium speed until stiff peak.
Making the batter
Sift cake flour, baking powder, and salt 3 times into a bowl. Set aside.
In a separate large mixing bowl, beat egg yolks using a wire whisk or hand mixer. Add sugar and submerge bowl in warm water. Beat until sugar completely dissolves.
When sugar is dissolved, remove bowl from warm water and continue beating until color turns pale. Add canola oil, coconut milk, and buco pandanness flavoring. Mix well until fully incorporated.
Tip in cake flour mixture and gently fold with the wet ingredients. Continue folding until no traces of flour is left.
Using a rubber spatula, add 2 scoops of meringue and mix in with the batter one at a time. When completely incorporated, transfer the batter into the meringue bowl and fold in until fully combined.
Fill two baking pans with equal parts of batter. Tap the baking pans a couple of times on top flat surface to release air bubbles.
Bake in preheated oven for 20-25 minutes or until top of chiffon cake turn golden brown and inserted toothpick come out clean.
Carefully remove from the oven then immediately flip the pans onto a wire rack lined with parchment paper and release the cakes. Turn them topside up and let it cool.
Making the cream filling (optional)
While waiting for the chiffon cakes to cool down, you can make the cream filling by whipping the cream with hand mixer. Add in the powder sugar carefully until smooth and creamy.
Take one of the chiffon cake and spread cream filling on top then place the other chiffon cake on top of the cream filling. Slice to preferred serving size. Bon appetit!