01 - Preheat oven to 350°F. Grease an 8-inch round cake pan and line the bottom with parchment paper.
02 - In a medium bowl, whisk together the all-purpose flour, matcha powder, baking powder, and salt until evenly distributed. Set aside.
03 - In a large mixing bowl, beat the room-temperature butter and granulated sugar together using an electric mixer until the mixture becomes light and fluffy, approximately 3 minutes.
04 - Add the eggs one at a time, beating well after each addition until fully incorporated. Stir in the vanilla extract.
05 - Add half of the dry ingredient mixture to the wet ingredients and mix gently until just incorporated. Pour in the whole milk and stir to combine. Fold in the remaining dry ingredients and mix until the batter is smooth with no dry pockets.
06 - Pour the batter into the prepared cake pan and use a spatula to smooth the top evenly.
07 - Place the pan in the center of the oven and bake for 28 to 32 minutes, or until a toothpick inserted into the center of the cake comes out clean.
08 - Allow the cake to cool in the pan for 10 minutes, then carefully invert it onto a wire cooling rack to cool completely.
09 - Whisk together the powdered sugar and matcha powder in a small bowl. Dust the mixture evenly over the completely cooled cake before serving.