Tokyo banana roll

Recently I've been doing a lot of blog-hopping and my to-do list is getting longer and longer. Definitely I won't be able to bake or cook as fast as I bookmarked an interesting recipe. Often times, the 'old' bookmarked recipe get forgotten and the 'new' bookmarked recipe cut the line, like This one.

It looks like a straight-forward recipe and I have 2 over-ripen bananas in the fridge. I'm not fully satisfied with the end result as my custard cream turned out slightly runny, and the sponge cake looks kinda rough when I sliced into halves. That's why you will see that I've some brown banana rolls too.

I guessed if I've followed the originator steps 100%, I should be able to achieve a much better results for the sponge cake. As for the custard cream, I noticed that it was quite runny when cooking it, but thought it will solidify after cool which didn't change much eventually. I may have to add more corn starch the next time I prepare this (which won't be too long...hehehe).

I've copied the recipe here for ready reference. Or you can also watch this Youtube video on How to Make Tokyo Banana Roll  https://www.youtube.com/watch?v=D6wxd72vM_A&feature=youtu.be. 

Banana custard cream 

Ingredients/ method: 
100g banana, without skin
1 egg
1 tbsp corn starch
3 tbsp granulated sugar (I reduced to 2 tbsp)
150ml milk
a few drops of vanilla extract

1. In a bowl, mash banana with a fork
2. Add all other ingredients and mix well.
3. Strain the mixture through the sieve into a saucepan. 
4. Put on low, stir constantly, and stop the heat when the cream starts to thicken. Mix well with the remaining heat. Add a few drops of vanilla extract. Leave to cool completely.
5. Transfer the cream into a pastry bag or into a dish covered tightly with plastic wrap. (Make sure the cream sticks to the plastic wrap to keep from drying out). Chill in the fridge. 

Sponge cake
Ingredients/ Method
2 eggs
50g superfine sugar
35g cake flour
20g milk, room temperature

1. Beat eggs and sugar with whisk in a metal bow. Placed it over the pan of hot water and melt the sugar and warm them up to 40 deg C. (I did not measure the temperature. When the egg white is warm to touch by hand, and there's no sugar grains, it should be ready.) 
2. With an electric mixer, beat the batter on high speed for about 5 mins until white and fluffy. Then on low speed, beat for about 2 mins to set the texture. 
3. Sift in the flour and fold together with spatula for about 10 mins. 
4. Add milk and fold together with spatula for about 50 times until combined. (For Steps 3 & 4 , I used my KA on speed 1.) 
5. Spread the batter in a lined 9" square tin. Drop the pan lightly on the counter to raise the air bubbles out of the batter. 
6. Bake at preheated oven 180 deg C for 11-12 mins or until lightly brown. 
7. When it's done, drop the pan lightly to prevent shrinking. 
8. Remove the sponge cake from the pan by lifting the wax paper and place it on a wire rack to cool.
9. When the cake is cool, remove the parchment paper and place the sponge cake on the parchment paper with brown side up.

Assembly

1. Cut the sponge cake into 4 squares. Then cut them by half horizontally (will have thin slices, about 0.2 inch).
2. Place the cake on plastic wrap (with brown side up), pipe out the banana custard cream, roll and securely twist the ends like a candy.
3. Serve chill.