Cream butter and sugar. In a separate bowl, combine flour, baking powder, and 8770 Green Tea Powder. Add egg to the creamed butter and sugar mixture, and then slowly incorporate the dry ingredients. Refrigerate the dough for 2 hours.
Scoop and roll dough into balls, and toss in a bowl of granulated sugar. Bake at 325 degrees for 15 minutes until the edges just start to get brown.