Prep the Ingredients: In a small bowl, whisk together 1 cup all-purpose flour, 2 tablespoons matcha powder, ⅜ teaspoon kosher salt, and ⅜ teaspoon baking soda. Roast and chop ¼ cup nuts of your choice. Dice 6 tablespoons unsalted butter into cubes.
Brown the Butter: Place the cubed butter in a pot over medium-high heat. Stir or swirl it continuously. Once it melts, keep browning for about 2 to 3 minutes until it turns golden and smells nutty. Remove from heat, pour into a heatproof bowl, and chill in the fridge for 5 minutes.
Mix Butter and Sugar: Add ¼ cup brown sugar and 2.5 tablespoons white granulated sugar to the cooled brown butter. Whisk until smooth and combined.
Add Egg and Yolk: Add 1 egg and 1 egg yolk, then whisk for about 3 to 5 minutes, until the mixture becomes lighter in color, thicker, and leaves a ribbon-like trail that slowly fades when lifted.
Combine with Dry Ingredients: Fold the dry ingredients into the wet mixture with a spatula. Be gentle—don’t overmix.
Add Chocolate and Nuts: Carefully fold in ½ cup chocolate chips of your choice and your chopped nuts.
Chill the Dough: Cover the dough and let it chill in the fridge for at least 2 hours or up to 3 days. In a rush? You can skip this step, but chilling the dough makes the cookies denser and chewier. For the best texture, I highly recommend it!
Bake the Cookies: Move the oven rack to the middle. Preheat your oven to 350°F (325°F for convection). Let the dough sit for about 10 minutes at room temperature to soften. Scoop it onto a baking sheet lined with parchment or silicone mats (see Note 5). Bake for about 8 to 10 minutes until the surface gets slightly brown. Keep an eye on them—don’t overbake! Bake one sheet at a time for best results.
Cool the Cookies: Sprinkle a little sea salt on top, then let the cookies cool on the baking sheet for about 5 minutes, or until they’re firm enough to move. Transfer them to a rack and let them cool for another 15 to 20 minutes. Now, grab a glass of milk and enjoy!