Preheat the oven to 350° F. Line a rimmed cookie or baking sheet with parchment paper and set aside for later.
Measure the flour, baking powder, Matcha tea powder, sugar, and salt in a large mixing bowl. Whisk to blend the dry ingredients to thoroughly mixed.
2 cups all-purpose flour, 1 tablespoon baking powder, ¼ cup Matcha green tea powder, ¼ teaspoon salt, 3 tablespoon sugar
Add the grated butter to the dry ingredients. Toss lightly with a fork to coat all the butter. Add grated butter and toss with the fork to distribute the butter though the flour. Add the white chocolate chips and toss lightly again. Make a well in the center of the bowl contents.
¼ cup butter, ½ cup white chocolate chips
In a small bowl, whisk the egg and heavy cream together. Pour into the well of the flour mixture. Mix quickly and lightly with a spatula, scraping the sides to mix all the flour in. The dough should come together as a rough dough ball, kind of shaggy.
1 cup heavy cream, 1 large egg
Turn the shaggy ball of dough onto a lightly floured board or counter top. Flour your hands and lightly pull the dough together into a disc that's about 8" in diameter and 1" thick.
Place the scone dough disc on the parchment paper lined cookie sheet or baking pan. Cut into 8 wedge pieces and spread out with 1" space apart.
Bake for 13-15 minutes, being very careful not to over bake (the matcha browns and burns easily).
Remove from oven and wait 10 minutes (they will continue to finish baking) until transferring to a wire cooling rack.
Mix the powdered sugar and milk to make an optional thin icing to drizzle over the cooled scones before serving.
½ cup powdered sugar, 2 teaspoons milk