• Preheat oven to 160C.

Egg Yolk Batter

• Melt butter and then add in the flour, vanilla essence, milk, eggs and egg yolks in that order.
• Mix till smooth.

Meringue

• Over a bain marie, beat the egg whites until frothy, add in the lemon juice.
• Add the sugar into this gradually and beat till firm but not yet stiff peak.

Mix

• Mix 1/3 of the meringue into the egg yolk batter to thicken it. Then add the rest of the meringue till incorporated.
• The pan I used was 20cm round. It is a pretty tall cake.

Bake

• Put a rack above a pan of hot water. The cake should stand about 1/4 way above the floor of the oven.
• Bake at 150C for 50 minutes.

Unmold

• When baked, turn the cake upside down for 5 minutes.
• Remove the liner and serve.