Preheat oven to 180 degree celsius.
On a double boiler, melt butter and white chocolate.
Once melted, remove from heat and whisk in matcha powder and sugar.
Once mixed, whisk in the eggs one by one until thoroughly combined.
Sift and stir in flour and salt.
(Optional) Add in chopped almonds and mix well for extra texture.
Put it in a 8 inch pan, lined with baking paper, and bake it in the oven for 25 mins.
Once done, leave to cool before cutting.