Prepare your ingredients: Start by gathering all your ingredients. Sift the all-purpose flour, baking soda, cornstarch, and matcha powder into a medium bowl. Sifting helps you to remove lumps and evenly mix the dry ingredients. Set the butter to room temperature and set aside.

Prepare the butter mixture: In a large mixing bowl, use an electric mixer to combine the butter, brown sugar, eggs, and vanilla extract. Beat until fully mixed.

Mix dry and wet ingredients: Gradually add the dry ingredients to the wet ingredients, stirring until a dough forms. The dough should have a vibrant green color from the matcha. If it looks too dry, add a teaspoon of hot water to help it come together.

Fold in white chocolate chips: Gently fold in the white chocolate chips using a silicone spatula.

Chill the dough: Cover the cookie dough with plastic wrap and chill in the fridge for at least 15 minutes to help it hold its shape when baked.

Preheat and prepare the baking sheet: While the dough chills, preheat your oven to 350°F while lining your baking sheet with parchment paper or silicone mats. These prevent the cookies from sticking.

Form the dough balls: Use a cookie scoop to form uniform dough balls. Place them on the prepared baking sheet, leaving space between each one as they will spread during baking. Press the pecan and almond slices on top of each cookie.

Bake cookies: Bake the cookies for 10-12 minutes, or until the edges are set but the centers remain soft. They will continue to firm up as they cool on the baking sheet.

Cool and enjoy: Let the cookies cool on the baking sheet for 1-2 minutes before transferring them to a wire rack. Enjoy!