Preheat oven to 170C (340F).

Sift flour twice to ensure a light texture.

In a bowl, combine egg yolks and 2 2/3 tablespoons of caster sugar. Mix well until pale and smooth.

Add 3 7/8 tablespoons of water and 4 3/8 tablespoons of canola or corn oil to the egg yolk mixture. Blend together thoroughly.

Gradually add the sifted flour to the wet ingredients, mixing well with a hand whisk until a smooth batter forms. Set aside.

In a separate, clean bowl, prepare the meringue.

Combine 3/4 cup of caster sugar and 1 3/8 tablespoons of corn flour.

Beat egg whites until foamy.

Gradually add half of the sugar and corn flour mixture to the egg whites, continuing to beat for a few minutes until partially incorporated.

Add the remaining sugar and corn flour mixture to the egg whites and beat until the meringue is glossy and forms stiff peaks.

Gently fold one-third of the meringue into the egg yolk mixture to lighten it.

Fold in the remaining meringue until fully incorporated, being careful not to deflate the batter. Alternatively, slowly pour the egg mixture into the meringue at low speed using a machine, then stop and fold with a spatula.

In a small bowl, combine 1 teaspoon of matcha powder with 1 tablespoon of hot water to create a matcha paste.

Take one-quarter of the plain batter and mix it thoroughly with the matcha paste to create the matcha batter.

Alternately spoon the plain and matcha batters into an ungreased 21cm (8-inch) chiffon cake pan, layering them until all the batter is used up.

Gently shake and bang the pan on the table top to release any trapped air bubbles.

Use a chopstick or skewer to gently stir the batter, creating a marble swirl pattern.

Smooth the surface of the batter with a rubber spatula.

Place the cake pan in the preheated oven and bake for approximately 45-50 minutes.

After 45-50 minutes, switch the oven to the lower grill setting and bake for an additional 5 minutes to ensure the top is golden brown.

Once the cake is done, remove it from the oven and immediately invert the pan onto a wire rack or bottle.

Leave the cake to cool completely in the inverted pan. This prevents it from collapsing.

Once the cake has cooled completely, carefully run a knife or spatula around the sides of the cake to loosen it from the pan.

Gently remove the cake from the pan and serve.