Let egg white cool in a fridge. Preheat a oven to 392 ºF.

Add granulated sugar to egg yolk and mix. And warm it in hot water while mixing until it reaches body temperature. Let grape seed oil warm in the hot water on extremely low heat.

Mix the egg yolk until it becomes whitish and heavy. Add the grape seed oil little by little while mixing. It's important that the batter is smooth.

Make juice with banana and milk. Add the banana juice to the egg yolk batter little by little while mixing.

Put the egg white from the fridge and make meringue. Beat it lightly until it becomes watery. Whip it with a hand mixer on high speed.

Add granulated sugar in 2 parts after it becomes white and fluffy. Whip it to soft-peak stage and switch to low speed. Whip it slowly for 2 minutes.

Sift cake flour, bread flour and baking powder together. Add the flour to the egg yolk batter and mix well.

When powderiness disappears, mix strongly about 30 times to make it a little sticky. Add the meringue in 3 parts. Mix well at first time.

From the next, mix it while scooping and dropping until it gets smooth.

Mix the side and bottom with a spatula. Pour it into the mold without gaps. Drop the mold lightly 2-3 times to remove big bubbles (Please press down on middle cylinder).

Bake it at 338 ºF for 35 minutes. Drop the mold lightly and upside down and let it cool completely (over 3 hours).

Push down the cake to half the height along the mold. Push down around the cylinder too. Turn it upside down. Push the bottom while rotating the mold. (The cake will come down gradually.)

Lift the side mold and remove it from the cake. Push the side of the cake and peel it off from the mold.

Add hot heavy cream to chopped chocolate. Wait for 30 seconds as it is and melt chocolate. Spread the chocolate on top of the cake and put chopped almonds.