Preheat the oven to 350 degrees.
In a large bowl, beat the butter and sugar together until light and fluffy, about 2-3 minutes. Add in the eggs and vanilla and beat until creamy.
1 cup butter, 1 ¾ c sugar, 2 eggs, 1 tsp vanilla
Add in the flour, salt, baking powder, baking soda and matcha powder and mix. The dough will be stiff, but be patient as it will come together.
3 cup flour, 1 tsp salt, 1 tsp baking powder, 1 tsp baking soda, 6 tsp matcha powder
Use a 1 ½” Tbsp cookie scoop to achieve uniform cookie sizes and scoop the dough onto a baking sheet, spacing the cookies about 2-3” apart.
Place in the oven and bake for 10-11 minutes, just until the edges start to turn golden. Remove and let the cookies cool on the pan for about 3 minutes before transferring to a cooling rack to come to room temperature.
To make the filling, place the butter in a medium sized bowl and beat for 1-2 minutes until the butter lightens in color. Add in the vanilla and powdered sugar and beat until creamy.
½ cup butter, 2 cup powdered sugar, 2 tsp vanilla
Place the filling into a piping bag with a circle tip (#12 shown) and pipe the filling onto one side of the cookie in a circular motion. Top with another cookie and gently press the cookies together so the frosting adheres to both sides and creates a sandwich. Repeat until all the cookies are paired into sandwiches.
Store any leftovers in an airtight container for up to 4 days.