Sift flour, matcha powder and baking powder. Set aside.
Use an electric hand mixer to beat egg whites and 2 tablespoons sugar until stiff peaks form.
In another bowl, beat the egg yolks and the remaining sugar until color is lightened. Add oil and water, continue beating until thoroughly combined.
Fold in flour mixture until combined.
Gently fold in 1/3 of the egg whites until incorporated into the green tea batter. Then fold in the remaining egg whites until no whites remain.
Pour the batter into the ungreased bundt pan and spread evenly. Bake for 25 to 30 minutes, or until springy to touch.
Turn the cake upside down on a plate when it’s hot. Let it cool completely.
Use a thin offset spatula to run around the side of the cake to loose it.
To prepare the whipped cream, beat the cream until soft peaks form. Add powdered sugar and continue beating until firm. Use an offset spatula to spread whipped cream all over the cake. Chill the cake in refrigerator.
To prepare ganache, place chocolate and heavy cream in a medium heatproof bowl over a pot of simmering water. Stir the mixture using a wooden spoon until melted and smooth, about 5 minutes. Remove from heat and let cool slightly. Spoon ganache over the top of the cakes. Gently push the ganache to the sides to create dripping effect.