In a mixing bowl, mix together butter, powdered sugar, lemon zest, lemon juice, and matcha. In another bowl, combine flour, cornstarch, and salt then add to mixture in the mixing bowl. Mix to form dough.

Weigh out 6 grams of dough (roughly about a tablespoon) and roll into a ball. Place balls on a parchment lined sheet tray and cover with saran wrap to chill in the refrigerate for at least an hour. The dough can be kept in the freezer for up to a month.

Preheat oven to 350°F. With balls spaced at least an inch and a half apart on the parchment lined sheet tray, bake for 15 minutes on the middle rack.

Combine matcha sugar ingredients in a large resealable plastic bag.

Once they have cooled a bit but still slightly warm, toss 5–7 cookies in the matcha sugar mix in the plastic bag. Toss again in matcha sugar mix once cooled.