Preheat oven to 450 degrees F (230 degrees C). Grease an 11x7 inch pan. Line bottom with parchment paper and grease and flour paper. Sift together the flour, cornstarch and 1 tablespoon green tea. Set aside.

In a large bowl, beat eggs, yolks and 6 tablespoons sugar until tripled in volume, about 5 minutes. Fold flour mixture into whipped eggs. In a large glass or metal mixing bowl, beat egg whites with cream of tartar until foamy. Add 2 tablespoons sugar, continuing to beat until stiff peaks form. Fold 1/3 of the whites into the batter, then quickly fold in remaining whites until no streaks remain. Spread batter into prepared pan.

Bake in the preheated oven for 8 to 10 minutes, or until center of cake springs back when lightly tapped. Sprinkle with confectioners' sugar, then invert onto a flat surface. Let cool.

To make the Green Tea Whipped Cream: In a medium bowl, whisk the heavy cream with the 4 teaspoons superfine sugar and 2 teaspoons green tea until stiff peaks form.

To make the Decorative Green Tea Marzipan: Knead the almond paste with 1 teaspoon green tea. Roll out between 2 sheets of plastic wrap, or lightly dust with confectioners' sugar while rolling.

When cool, remove parchment paper from bottom of cake. Cut cake horizontally down the middle to make two layers. Spread bottom layer with 1/2 of the whipped cream, then cover with top layer of cake and spread top with remaining whipped cream. Cut assembled cake into 12 pieces using a knife or decorative cutters. Roll out the marzipan and cut into 12 pieces to match the shapes of the cakes. Place the decorative marzipan pieces on top of cakes.