Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a medium bowl, whisk together the flour, matcha powder, baking soda, and salt until well combined.
In a large bowl, cream together the softened butter, granulated sugar, and brown sugar using an electric mixer until light and fluffy.
Add the egg and vanilla extract to the butter mixture, beating until fully incorporated.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
Fold in the white chocolate chips and chopped macadamia nuts, if using.
Using a tablespoon or a cookie scoop, drop rounded balls of dough onto the prepared baking sheet, leaving enough space between each cookie to allow for spreading.
Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.
Notes
Optional macadamia nuts can be added for extra crunch.