Preheat the oven to 360 degrees F (180 degrees C). Lightly brush just the bottom of an angel food cake pan with oil; do not oil the sides.
Dissolve the matcha in 3/4 cup (170 milliliters) hot water in a heatproof bowl or cup. Set aside and let cool to room temperature.
In a large bowl, whisk together the flour, baking powder and salt. Using an electric mixer on high speed, beat the egg whites with 3 tablespoons of the sugar until the meringue holds medium-stiff peaks. Spoon the meringue gently into a large bowl, taking care not to lose the air in it. In a separate bowl, beat the yolks and the remaining sugar on high speed until pale yellow and fluffy. Reduce the speed to low and slowly add the green tea and oil in a slow and steady stream down the side of the bowl. Beat until completely incorporated. Working in 3 batches, gently fold the dry ingredients into the egg yolk mixture. Next, very gently fold in the egg white mixture in 3 batches as well.
Carefully pour the batter into the pan and bake, turning about halfway through, until an inserted toothpick comes out clean, about 50 minutes. Let the cake cool in the pan upside-down on a cooling rack until completely cool. Use a thin metal offset spatula or a thin knife to run along the sides and metal core of the pan to unmold. Slice using a serrated knife and serve with Vanilla Chantilly Cream.
Place the sugar in a bowl and pour the cream over. Add the vanilla seeds and whisk on medium high using an electric mixer until soft peaks form and it is smooth and creamy. Do not over-whisk.
Don't over-mix this batter when incorporating the egg whites. Fold them in very gently using a rubber spatula. You can substitute any other flavoring instead of the green tea. Try espresso, citrus or vanilla, too. Just keep the amount of water or liquid the same. It is a very versatile cake base.