Preheat the oven to 180°C. Roughly chop the chestnuts, set aside.
Melt the butter then pour it into a large mixing bowl, let it cool completely. Sieve the flour gradually into the butter and combine well until you get a smooth mixture.
Add the eggs and sugar to your bowl, combine well. Gently fold in the Matcha and the chestnuts. Stir until the batter becomes evenly green.
Spoon the batter into 4 mini bundt cake tins (or one medium one) and bake, in the middle of the oven, for 25-30 minutes.
Serve it warm or let it cool, then dust it with icing sugar.