Matcha-Mascarpone Layer Cake

Preheat the oven to 340 degrees F (170 degrees C). Line the bottom of two 9-inch round cake pans with parchment paper.

Mix cake flour, salt, and baking powder thoroughly.

Whisk matcha powder into the hot milk until no lumps remain. Let cool.

Beat yolks in a bowl using an electric mixer; add superfine sugar and blend until dissolved. Whisk in oil until thoroughly combined. Add the matcha-milk mixture and mix well. Sift in 1/4 of the flour mixture at a time, mixing batter well after each addition.

Beat egg whites in a glass, metal, or ceramic bowl until foamy. Add cream of tartar and whisk well. Add 1/4 of the sugar at a time, mixing well after each addition. Continue to whisk until stiff peaks form, or until mixture looks like shaving cream and no bubbles are visible. Do not overmix.

Gently fold 1/3 of the egg white mixture into the yolk batter using a spatula. Repeat with the rest of the egg whites. Pour batter into the prepared cake pans. Chill a clean metal bowl and whisk attachments in the freezer.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, 25 to 30 minutes.

Remove from oven. Invert pans and allow to cool completely; this will prevent the cakes from sinking.

Beat heavy cream and confectioners' sugar together in the chilled metal bowl until soft peaks form. Set frosting aside in the refrigerator.

Beat mascarpone cheese, heavy cream, confectioners' sugar, and matcha powder in another bowl until filling mixture begins to stick to the whisks.

Run a thin knife along the edges of the baking pans to remove the cakes. Spread the mascarpone filling over 1 side of each cake. Place 1 cake on a serving plate, filled-side up; top with the other cake, filled-side down. Spread frosting over the surface.