In a medium saucepan over medium heat, melt butter and continue cooking, swirling occasionally, until it foams, then turns golden brown with nutty aroma. Remove from heat and let cool slightly (about 10 min).

In a large bowl, whisk together flour, matcha powder, baking soda, and salt.

In a separate bowl, beat browned butter with granulated and brown sugars until slightly fluffy. Mix in egg and vanilla until combined.

Gradually stir dry ingredients into the butter mixture until just combined—don’t overmix.

Cover dough and chill in the fridge for 30 minutes to firm up.

Preheat oven to 350 °F (175 °C). Line baking sheets with parchment paper.

Scoop rounded tablespoons of dough onto sheets, spacing about 2 inches apart. Gently flatten each cookie slightly with your fingers.

Bake for 10–12 minutes, until edges are set and centers still appear soft.

Let cookies cool on the sheet for 5 minutes, then transfer to a wire rack to finish cooling.