I don’t make Swiss rolls, and I never thought I will make one, but I saw this cute Swiss roll in the net on some Japanese sites
first I did not understand any thing, but I find an English Japanese blog explain the technique, and it was easy so I go for it and make a simple design for the first time
1 cup Cake flour or all purpose flour
1 cup Sugar
4 tablespoons cooking oil
5 tablespoons hot water
1 tsp Vanilla extract
1 tea spoon baking powder
2 table spoons of cocco powder + 1 table spoon of water (or you can use food coloring instead)
Jam for filling
1.Preheate your oven into 180 c
2. Prepare your baking tray, line with parchment paper or baking sheet, grease some oil on it with a brush
3. Separate the egg white from the yolk
4. In a large bowl, mix egg yolks, vanilla extract, half amount of sugar, cooking oil and water together with a hand whisk, mix well and add in sifted flour, mix well again, set aside
5. Whisk egg white to foamy and add the other half of sugar, continue to whisk egg white to smooth peak form at medium speed
6. Take out 2 tbsp egg yolk mixture and 2 tsp egg white mix with cocco powder and the water,
7. Put the mixture in a freezing bag and make a small hole in its edge then pipe your design on baking tray
8. Put the tray in preheated oven 1 minute. Get it out and let it cool completely.
9. Fold 1/3 of the egg white to the egg yolk mixture, fold well with a rubber spatula and fold in the remaining egg white. Pour the plain mixture into your tray. Level the surface gently, knock the tray on table top to remove air bubbles trapped in the batter
10. Bake for 15 mints.
11. Turn sponge onto a plastic sheet. Gently peel off baking sheet from the bottom of sponge and invert the sponge with skin facing up. Spread an even layer of jam over top of sponge. Gently roll up the sponge to make a Swiss roll. (Place a tea towel underneath to prevent plastic sheet slip) Wrap with plastic sheet or cling wrap and chill it for one hour.
for more see this video for the method (in Japanese language)