1. Preheat oven to 350˚F and line muffin tin with paper liners. Set aside.
2. In a measuring cup, measure your milk and add vinegar. Stir a couple of times then set aside for a few minutes to sour the milk.
3. In a large bowl, sift together flour, matcha, baking powder, baking soda, and salt. Add sugar and whisk together until ingredients are combined.
4. Next, add soured milk and oil to dry ingredients and using a spatula or a wooden spoon, stir the ingredients together until well incorporated.
5. Divide batter evenly among the paper liners. Fill no more than 2/3 to 3/4 of the way per liner.
6. Bake in the preheated oven for 25 minutes, or until toothpick inserted in the middle comes out with a bit of crumb stuck to it. Remove and allow cupcakes to slightly cool in the tin a few minutes before removing and placing on a wire rack to cool completely.

To make the icing

1. In an electric mixer fitted with the whisk attachment, beat all ingredients until icing is silky smooth. If you find the icing is too soft, cover bowl with plastic wrap and place in the fridge to help it solidify. Remove and spoon or pipe icing onto cupcakes.
2. Dust iced cupcakes with matcha powder.