• Preheat oven to 160C.

To make egg yolk batter

• In a large mixing bowl, add sugar and egg yolk together.
• Whisk until pale and creamy, ribbon stage.
• Add coconut milk, mix well.
• Add yam puree, mix well.
• Slowly drizzle in oil while mixing.
• Add sieved flour and whisk until no trace of flour can be found.

Egg white meringue

• In a clean mixing bowl, add egg whites and cream of tartar.
• Whisk until soft peaks formed.
• While whisking, gradually add sugar and continue whisking until stiff peaks formed.
• Be careful not to overbeat your meringue or it will curdle.

Mixing the batter

• Add your meringue in 3 batches (1/3) into your egg yolk mixture.
• Fold it in gently but quickly with a spatula or hand.
• Fold in the next batch until done.
• Be careful not to deflate your batter.
• Divide your batter into 3 equal portions.
• Portion 1: Leave it as it is.
• Portion 2: Fold in the 1/4 tsp yam essence
• Portion 3: Fold in other 1/2 tsp yam essence
• Carefully and slowly pour Portion 1 batter into an un-greased chiffon pan first.
• Then pour portion 2 gently on top, and portion 3 last.
• Bake for 15 minutes at 160C, and 20 minutes on 150C.
• When done, invert to cool completely before unmoulding.