Preheat the oven to 140°C.
Prepare pandan juice by blending pandan leaves with water and straining.
In a bowl, whisk egg yolks with sugar until well mixed. Add oil. Mix until combined. Add pandan juice and then mix well. Sift in self-raising flour and cornstarch and whisk until smooth with no lumps.
In a separate clean bowl, beat egg whites until frothy. Add lemon juice and gradually add sugar in 3 batches. Beat until stiff peaks form. The tip should pointed up when the whisk is lifted.
Scoop up 1/3 of the meringue and mix into the egg yolk batter using a whisk. Mix well. Then pour the batter into the meringue. Mix well using a whisk. Don’t over whisk it. Once everything combines, you can stop whisking. Then use a spatula to make sure the corner and edges of the meringue are well incorporated into the batter.
Pour batter into a square 8 inch pan (do not grease). Tap the pan lightly to release air bubbles.
Bake at 140°C for 50 minutes. Then increase to 160°C for 5-10 minutes or until the top of the cake turns golden brown.
After baking, tap the mould onto the table a few times to release trapped air. Then wait for it to cool down. Takes about 20 minutes.
Once cool, run a knife around the edges to release. Remove from mould. Slice and serve.