1. Preheat oven to 350F
2. In a small pot, heat up the milk, water for the cupcake, and water for the frosting (8 tablespoons of water total) steep 2 tablespoons of tea in it for 5 minutes. Strain out the tea and set the milk/water mixture aside to cool.
3. In a mortar and pestle (or using a spice grinder), grind 1 tablespoon of tea.
4. Mix the ground tea, the sugar, flour, salt, baking powder, and baking soda together in a large bowl.
5. In a medium bowl, whisk together 1/2 cup of the cooled down tea/milk/water mixture, the egg, vanilla extract and neutral oil.
6. Pour the medium bowl of wet ingredients, into the large bowl of dry ingredients.
7. Remove two tablespoons of the tea/milk/water mixture from your pot to use in the frosting, set aside.
8. Take the rest of the tea/milk/water mixture (there should be 6 tablespoons left) and bring it to a boil. Pour boiling tea/water/milk into the cupcake batter, stirring until fully combined.
9. Pour batter into cupcake tin, filling each one up only halfway.
10. Bake for 15-20 minutes (a toothpick should come out clean).
11. Use an electric mixer to beat all of the ingredients (including the 2 tablespoons of cooled-down reserved tea) together.