Mirror Chocolate Banana Roll 鏡面巧克力香蕉蛋糕卷

Crave for secret recipe's chocolate banana cake? Here we go, same materials but turn into swiss roll.
You would ask for more after a slice!

Ingredients:
Cake Base
Cake flour 45g, corn flour 15g, cocoa powder 10g;
Egg yolks 4pcs, sugar 32g, vegetable oil 30g, milk 50g;
Egg white 4pcs, sugar 40g, lemon juice few drops;

Fillings
Whipping cream, 150g, cocoa powder 1tbsp mix with 1tsp hot water, sugar20g;
banana 1pcs(don't overripe)

Choco Mirror
Baking chocolate 50g, whipping cream 60g;