In a large bowl, cream the butter and the sugar until fluffy, about 3 minutes.
Add the vanilla extract and the ground almonds and mix until all the ingredients are thoroughly incorporated. Slowly mix in the flour and matcha.
Make a ball with the dough and flatten with the ball of your palms. Place onto un-greased cookie sheets, leaving several inches between for expansion.
Bake 12-15 minutes until lightly browned. Cool the cookies on the sheet for 1 minute, then remove to a rack to cool completely. When cooled, sprinkle with confectioners' sugar.
