This cake delivers a combination of green tea and white chocolate that tastes like Green Tea Latte.

You can also use whatever green tea sponge cake you'd like the mousse is delicious on its own.
Using a "chasen" (tea whisk used in Japanese tea ceremony) during Step 25 will make the mixing easier.
If you are decorating the cake with whipped cream, remember that you are using the sifted green tea powder to dust the cake.