In a bowl, stir together flour, matcha powder, and baking powder.
Using a stand mixer or an electric hand mixer, cream together butter and sugar on high speed for three minutes.
Then, add vanilla extract and eggs and mix together until all ingredients are incorporated together. You may need to scrape down the side of the bowl with a rubber spatula.
Next, add wet ingredients to dry ingredients and stir just until smooth.
If adding white chocolate chips, stir them in at this time.
Cover the bowl with plastic wrap and chill in the refrigerator for 1 hour.
Preheat oven to 350°F and prepare two bowls – one with granulated sugar and one with powdered sugar.
Once the dough has chilled, scoop out spoonfuls and roll into 1″ balls (it will still be a bit sticky and that’s okay).
Roll dough balls first in granulated sugar and then in powdered sugar.
Place on a baking sheet lined with parchment paper and bake for 15 minutes.
Let cool slightly and enjoy!