To Make the cake batter

1. Preheat your oven to 160°C fan (350°F). 
2. Prepare an unlined 6-inch tube pan (15 cm). Do not grease it.
3. In a medium mixing bowl, sift the cake flour, green tea powder and baking powder. Set aside.
4. In a separate large bowl, whisk the egg yolks and 12g sugar until pale and slightly thickened.
5. Add the milk, vegetable oil, and vanilla extract,  mix well.
6. Sift in the dry ingredients mixture and continue to  whisk until everything is just combined.  Then stop the mixer and gently mix by hand until smooth consistency.

To Make the Meringue

1. In a clean, grease-free bowl, add lemon juice and whisk the egg whites with a hand mixer until foamy.
2. Gradually add 54 g sugar, one-third at a time, beating until stiff peaks form.

To Combine the Mixtures

1. Take one-third of the meringue and fold it into the egg yolk batter to lighten it.
2. Gently fold in the remaining meringue in two additions, using a spatula to maintain the airy texture.
3. Pour the batter into the unlined chiffon pan and shake the pan to smooth the top.
4. Lift the pan up a few inches and drop it against the work surface to release any trapped air bubbles.  Also, run a skewer into the batter to get rid of the small air pockets to achieve the smooth crumb. 

To Bake and Cool the Cake

1. Bake in the preheated oven 30 – 35 minutes, or until the top is set and a skewer inserted comes out clean.
2. Immediately invert the cake pan and let the cake cool completely upside down to prevent collapse.
3. Once cooled, run a knife around the edges to release the cake.
4. Place the cake on your desired plate or cake stand.  
5. If there is a dome on top of the cake, you can trim it off to get a completely flat surface for decorating.  (optional)

To Make the Matcha Whipped Cream (Optional)

1. Place a mixing bowl in the fridge for 15 – 30 mins before whipping the cream.
2. Add the double cream and vanilla extract in the chilled mixing bowl.  Then sift in matcha powder and icing sugar.  
3. Add a pinch of salt before whisking the cream mixture.  Whisk at medium speed using a handheld mixer until soft peaks form.  
4. Cover the bowl with a lid and place it back in the fridge until needed.

To Decorate the Cake (Optional)

1. Frost the cake with a thin layer of matcha whipped cream.  Place it in the fridge for around 15 mins to set.
2. Once it is set, apply another layer of matcha whipped cream and smooth it out with a dough scraper.  
3. Pipe on top of the cake for your liking and dust it with matcha powder.  
4. Slice and enjoy it with a cup of coffee!