Preheat oven to 325 degrees.

Cream butter and sugar with mixer until light and fluffy. Add egg yolks, vanilla and sour cream and mix until combined.

Stir baking powder, salt, matcha powder and flour together in separate bowl.

Combine dry ingredients with creamed ingredients and mix until smooth. Place dough onto cookie sheet and press flat, then let rest for 30 minutes in refrigerator.

Roll out dough to ½” thickness on lightly floured surface and cut cookies with cookie cutter.

Arrange on cookie sheet 2” apart and bake for 10-15 minutes, until edges start to brown. Place cookies onto cooling rack.

Mix powdered sugar, water, butter and corn syrup together until smooth. Add more powdered sugar if icing is too runny.

Dip the top of each cookie into the bowl of icing, letting the excess icing drip over the sides of the cookie. While the icing is still wet, sprinkle the tea over the cookies using a small strainer. Let the icing set and dig in!