Matcha Shortbread with Chocolate Ganache

To make the Matcha Shortbread:

1. In the bowl of a stand mixer fitted with a paddle attachment or a large bowl, beat together the butter and powdered sugar until light and fluffy.
2. In a medium bowl, whisk together the flour, matcha, and salt.
3. Add the flour mixture to the fluffy butter and beat just until combined and smooth.
4. On a parchment-lined and lightly floured baking sheet, pat the dough into a disc, then roll into a sheet about 1/4 inch (6 millimeters) thick, adding just enough flour to prevent sticking. Refrigerate for 30 minutes.
5. Preheat oven to 350˚F (180˚C). Line two baking sheets with parchment or lightly grease.
6. Cut the refrigerated dough into individual cookies using a round cutter or other desired shape.
7. Carefully transfer the cut cookies to the prepared baking sheet and repeat with remaining dough.
8. If desired stamp the top of the cookies with a floured cookie stamp to create a design and refrigerate the baking sheets for 30 minutes.
9. Bake the chilled cookies in the preheated oven until set and barely golden on bottom, 9-12 minutes.
10. Allow the cookies to rest on the baking sheet for 5 minutes before removing to wire rack to cool to room temperature.

To make the Chocolate Ganache:

1. Pour the cream into a small saucepan and place over medium heat.
2. Place the chocolate chips in a medium bowl and set aside.
3. Once the cream is steaming, but not yet at a boil, remove from heat and pour over the chocolate in the bowl.
4. Allow to rest for 30 seconds, then whisk together until completely melted and smooth.
5. Cover the bowl and refrigerate, whisking occasionally, until firm enough to pipe.
6. Transfer the ganache into a bag fitted with a number 8-10 tip or a plastic bag with a small corner snipped off.

To assemble:

1. Pair together the cooled matcha shortbread cookies that are similar in shape.
2. Pipe the chilled chocolate ganache onto half of the bottom side of the cookies. Top, bottom side towards filling, with remaining cookies.
3. Very gently press until the ganache filling reaches the edges. Repeat with remaining pairs.