Preheat oven to 350° F. and line a standard muffin pan with parchment paper liners (parchment paper liners will keep the cupcakes from sticking since there's no butter or oil in them).

In a large bowl whisk together the dry ingredients. In a separate bowl whisk together the milk, yogurt, egg, sugar and vanilla extract. Pour the wet ingredients in with the dry and stir together just until combined.

Pour the boiling water into the batter and stir together until smooth, the batter will be fairly thin, this is okay. Fill the cupcake liners approximately 2/3 full with batter (I used a 3 tablespoon sized scoop). Bake the cupcakes for 14-18 minutes or until a toothpick inserted comes out mostly clean, but with a few crumbs attached. Cool the cupcakes on a wire rack completely before frosting them.

In the bowl of an electric mixer or using a handheld mixer, beat together the butter and cream cheese until smooth. Add in the matcha powder, pinch of salt and seeds of the vanilla bean or the vanilla bean paste or extract and beat until combined. Scrape down the sides of the bowl once to make sure everything is mixed together.

Add in the powdered sugar 1/4 cup at a time, beating slowly at first then on high once it's incorporated. Scrape down the sides of the bowl after each addition of powdered sugar. Once the frosting is smooth and fluffy, pipe or spread it onto the completely cooled cupcakes. The cupcakes can be stored in an airtight container in the refrigerator until ready to serve.