For the Cake Batter

1. Preheat the oven to 160℃.
2. Add the flour, baking powder and salt to a medium mixing bowl. Mix well and set aside.
3. Combine egg yolks and caster sugar in a large mixing bowl, whisk at medium speed using a hand-held mixer until the mixture thickens and turns pale in colour. This should take around 5 minutes.
4. Add milk and oil into the mixture and whisk together until well blended.
5. Place a sieve on top of the mixing bowl. Sift in the dry ingredients. Whisk the mixture at medium speed until the batter is well mixed. Set aside.

For the Meringue

1. Pour the egg whites and vinegar into a clean and dry mixing bowl. Use a hand-held mixer with a whisk attachment. Whisk them at medium speed until foamy.
2. Add the caster sugar into the egg whites in three portions. Allow around 1 minute in between adding each portion to allow the sugar to dissolve.
3. After adding all the sugar, turn the mixer to medium high speed and continue to whisk the meringue until it reaches its stiff peak form. You can check it by drawing the meringue out, using the whisk. If a firm peak is formed, it’s done.

Fold the Meringue into the Cake Batter

1. Scoop a small amount of the meringue and fold it into the egg yolk batter to lighten it.
2. Then pour the loosened cake batter back to the meringue, gently combining them using a whisk to maintain the airy texture.
3. Use a spatula to scrape down the sides and the bottom of the bowl to make sure everything is well incorporated.

Bake and Cool the Cake

1. Prepare a tube pan. DO NOT grease it.
2. Pour the cake batter into the pan at the same spot.
3. Hold the pan a few centimetres off the work surface and then drop it to get rid of any big air pockets trapped in the batter.
4. Run a skewer in the batter in a swirling motion, again to remove any remaining air pockets.
5. Shake the pan a few times to evenly distribute the batter inside the pan.
6. Place the pan on the lowest rack in the preheated oven and bake for around 40 to 45 minutes. DO NOT attempt to open the oven door while the cake is baking.
7. To check if the cake is done, no sooner than 35 minutes into the baking time, insert a skewer in the centre of the cake and if it comes out clean, it means the cake is done.
8. Take the cake pan out from the oven and immediately invert the pan onto a wire rack. Allow it to cool down completely.

Un-mould the Cake

1. Prepare a serving plate.
2. Run an icing palette knife along the edges and the funnel of the pan.
3. Invert the pan and use your thumbs to push the bottom of the pan down.
4. The cake should slide free from the pan leaving only the funnel in place.
5. Now run the palette knife along the base of the funnel. The cake should come out nicely.
6. Serve it on its own with a cup of tea / coffee or dust it with icing sugar for garnish. Enjoy!