Egg white mixture: in a large bowl, add the egg whites, sugar, and tartar powder, and beat until you see soft peaks when lifting the mixer up.
Step 3
3
Egg yolk mixture: in another large bowl, whisk egg yolk, milk, vegetable oil until evenly combined. Then add cake flour, matcha powder, baking powder, salt, and whisk to make sure there are no lumps.
Step 4
4
Take about ¼ of the egg whites and fold them into the egg yolk mixture, then repeat with the remaining egg whites until the batter is evenly combined.
Step 5
5
Transfer batter to the prepared large baking sheet pan and smooth the top with an offset spatula. Bake 350°F(180°C) for 10 mins until light golden brown. Let cool completely.
Step 6
6
Make the cream filling: in the bowl of a stand mixer, beat heavy cream and sugar at medium speed until pale and fluffy.
Step 7
7
Spread the cream frosting onto the matcha cake sheet and use the help of baking paper to roll it.