Preheat the oven to 350 degrees Fahrenheit.
Line a 12 cavity muffin tray with liners and set aside.
In a medium mixing bowl, whisk together all wet ingredients.
Whisk in the dry ingredients, making sure to spoon and level the flour.
Whisk until no clumps remain.
Add to your prepared tin, filling each about 3/4 of the way up.
Bake for 16-22 minutes, or until a toothpick comes out clean. 19 is usually perfect in my oven, but all ovens are different.
When the cupcakes are cooling, prep the buttercream.
Add the butter to a bowl of a stand mixer or large mixing bowl and beat for 2-3 minutes on low speed.
Add in the powdered sugar and beat until well combined. Add in a splash of milk as needed to thin.
Mix in the matcha, vanilla and pinch of salt.
When the cupcakes have cooled completely, frost and enjoy!