Add the butter to a small pot on the stove and cook over medium heat until the butter starts to brown. Turn off the heat and pour into a measuring cup, ensuring there is still ½ cup - add more butter if you need to.

Allow to cool completely before the next step.

Add the browned butter to the bowl of a stand mixer and add the egg. Beat with the paddle attachment, until creamy.

In a medium bowl, pass all the dry ingredients through a sieve.

Using a whisk, mix those dry ingredients together.

Scoop the dry ingredients into the wet, while mixing on low speed, until totally combined.

Fold in the white chocolate chips.

Empty the matcha cookie dough out onto some plastic wrap, then shape into a brick. Place into the refrigerator to cool.

Refrigerate the dough for a minimum of 2 hours. Overnight is great.

Using a small cookie scoop, scoop balls of dough onto a cookie sheet lined with parchment paper.

Refrigerate again for another 30 minutes.

Preheat the oven to 350°F.

Remove the cookies and place immediately into the oven on the middle rack. Bake for 10 minutes, then remove and allow to cool 5 minutes before transfering to a wire rack to cool completely.