Warm up the oven to 180°C (350°F). Sift the cake flour and sugar. Mash the banana well with a fork to for a paste.
Place the egg yolks into a bowl and mix. Agitate it bit by bit while adding in vegetable oil. Next add in the banana and milk, and mix until it thickens.
Lastly add in the sifted cake flour, and roughly mix it with a rubber spatula using large motions. It's okay as long as it mixes.
Add the egg whites to another bowl and beat with a hand mixer. After it has turned white, add in 1/3 of the sugar, beat some more, add in the next 1/3, and beat more.
Finally add in the remaining 1/3 and beat. Whip all of it until it forms a thick ribbon when it is lifted, and it doesn't fall out of the bowl when flipped upside down. Whip it for the last minute at a low speed.
Add 1/3 of the meringue to the bowl from Step 3. Mix it together well with an egg beater. Mix in another 1/3 in the same manner.
Add in the remaining 1/3 meringue, and stir just the surface as if drawing a large circle. In the end mix it lightly by scooping from the bottom and pulling it to the top.
After pouring into the mold, hit it while pressing down on the center to remove the air. Bake in the preheated oven for 35 minutes.
After baking, flip it upside down on a container that has some height, and let it cool.. After that, place into a plastic bag and let cool completely.
Use a toothpick in the center, and cut around the edges and bottom with a knife to remove from the mold. Enjoy with whipped cream.
Story Behind this Recipe
My friend who is good at making chiffon cakes taught me this recipe, so I wrote the tips down.
- Make sure to thoroughly whip the meringue for 8 minutes. - Blend the surface of the remaining 1/3 meringue, and then scoop it up in big scoops 5~6 times and mix together. - Use bananas that have ripened to the point where the skins have turned black.