Preheat oven to 400˚F (200˚C) and line a baking sheet with parchment or lightly grease.
In a large bowl, combine the flour, sugar, baking powder, matcha, and salt.
Cut the butter into the flour using a dough blade, your fingers, or forks until the mixture becomes coarse and no pieces are larger than a pea.
Mix in the egg, cream, and vanilla extract until just combined. Knead lightly to bring the dough together, but don't overwork. If too dry, slowly add a little more cream. Be careful not to add too much liquid. The dough should hold its shape, but not become sticky.
Place the dough on a lightly floured surface and press into a disc about 3/4 inches (2 centimeters) thick.
Use a 2 inch (5 centimeter) round cutter to cut out individual scones and place on the prepared baking sheet about 1 inches (2.5 centimeters) apart.
Bring together the excess dough and cut out as many rounds as possible.
Brush the tops of the scones with additional heavy cream.
Bake in the preheated oven until puffed and golden, about 12 minutes.
Allow to cool for 5 minutes before removing to wire rack. These scones are best the day they are made.