Prepare some hot water and a pan or tray that’s larger than the round cake pan for the water bath.

Preheat the oven to 150°C.

Separate the egg white and egg yolk into two different bowls. Place the egg whites in the refrigerator to chill. Eggs can be easily separated when cold.

Grease and line the pan with parchment paper and then over the bottom of the pan with a few pieces of aluminum foil.

Sift the flour to remove any clumps. Set aside.

Heat the oil. Pour the oil into a clean dry small pot and heat until the oil reaches 75-80°C (but not smoking)

Place the hot oil in a clean dry bowl. I used a warm water bath (around 50C) to place the bowl with oil.

Add the sifted flour into the heated oil and mix well with a balloon whisk or spatula. The heated oil cooked the flour slightly making a sticky batter. This is one of the crucial parts of this recipe.

Pour milk (at room temperature) into the flour mixture and mix well.

Add all the egg yolks (at room temperature) and mix until smooth. Set aside.

Place the cold egg whites in a clean large bowl. First, beat the egg white on low speed for about 30 seconds. Add the cream of tartar and beat for about one minute until foamy. Next, add all the sugar at once and continue beating on medium-high speed for about 3 to 4 minutes or until medium soft peaks form.

How To test Medium Soft Peak Meringue? Medium peaks hold their shape fairly well, but the tip of the peaks curl down slightly at the ends when you lift up your beaters.

Add about one-fourth of meringue to the yolk mixture and whisk well until no streaks are seen. This step helps the rest of the meringue to combine smoothly.

Now, very gently fold in one-third of the rest of the meringue into the yolk flour mixture until well combined. At this stage, I usually use a balloon whisk. Be gentle as much as you can not to deflate the meringue too much and make sure to scrape the bottom and sides of the bowl as needed.

Now transfer the base batter into the large bowl with the rest of the meringue. Gently scoop the batter from the bottom to the top with a spatula until the mixture is even with no white streaks while rotating the bowl.

Pour cake batter into the prepared pan at a height of 10 to 15 cm to break any air bubbles and gently shake the pan to level the batter out. Don’t add the batter stick to the spatula and bowl.

Pour warm water (around 60°C) to cover ¾ of the cake pan in water. Bake at 150°C for about 50 to 60 minutes or until the cake is golden brown on top and a toothpick inserted comes out clean. If it is still wet, bake for another 5 to 10 minutes more.