Preparation

• Prepare the pistachio paste. Place pistachios in a small food processor and pulse until very finely ground. Add oil and grind until the mixture forms a thick paste. It won't be smooth like peanut butter, but it will be thick and coarse.
• NOTE: you will need extra ground pistachios for topping the cookies, so I recommend grinding a bit more (around 90g), then remove 30g for later before adding the oil to make the paste.
• Prepare the cookie dough. Cream together butter with both sugars in the bowl of a stand mixer fitted with the paddle attachment or using an electric hand mixer for 3 minutes on medium speed until pale and fluffy. Scrape down the sides of the bowl and beat in egg and extracts until evenly incorporated and smooth. Mix in pistachio paste.
• Combine flour with matcha powder, baking soda, and salt in a medium bowl and whisk to blend evenly. Add it to the butter mixture and fold it in. Add chocolate chunks and fold them in until evenly distributed. The dough will be soft and sticky.
• Cover the bowl and refrigerate for 2 hours.
• Preheat oven to 350°F. Line two large cookie sheets with parchment paper.
• Use a 1.35-oz cookie scoop to scoop up dough and release it onto prepared baking sheets spacing them about 3 inches apart since these cookies spread a lot. Sprinkle the tops with extra ground pistachios.
• Bake for 10-12 minutes until golden around the edges. Transfer pan to a wire rack and let cookies cool for a minute before transferring individually to the rack to finish cooling. Sprinkle with flaky sea salt if desired!