Preheat your oven to 175°C (350°F). Line a baking sheet with parchment paper to prevent sticking.
In a saucepan over medium heat, melt the butter. Stir it constantly as it foams and turns golden brown. You’ll notice a lovely nutty aroma! Once done, take it off the heat and let it cool.
In a medium bowl, whisk together the all-purpose flour, matcha powder, baking soda, and salt until well combined.
In a separate bowl, whisk the cooled brown butter with the white sugar and raw sugar until smooth. Then, add the egg and whisk until it’s light and creamy.
Gradually fold the dry ingredients into the wet mixture. Stir just until combined. Gently fold in the white chocolate chunks, saving some to add on top.
Use a cookie scoop to place balls of dough on your lined baking sheet. Press the reserved white chocolate chunks onto each dough ball.
Bake for 10–13 minutes, or until the edges are golden and the centers feel soft. After baking, cool them on the sheet for 5 minutes before moving them to a wire rack.
For a special touch, sprinkle some flaky sea salt or add gold leaf on top.