• Preheat the oven to 350°F (180°C). Line 2 baking sheets with parchment paper or silicone baking mats.
• In the bowl of a stand mixer fitted with the paddle attachment, lightly cream the butter on medium-high speed just until the butter is smooth, 1 to 2 minutes. Do not incorporate air into the butter. Scrape down the sides and bottom of the bowl.
• Add the icing sugar, cornstarch, ground tea and salt and mix on low speed until the dry ingredients are fully incorporated into the butter. Increase the speed to medium-high and continue to mix until smooth, 2 to 3 minutes. Add the flour and mix on low speed until most of the flour has been incorporated. Increase the speed to medium-high and continue to mix until the dough is smooth, without whipping air into the dough, 1 to 2 minutes.
• Scoop 13 1½-tbsp portions of cookie dough onto each prepared baking sheet, leaving ample space between them. Gently press down on the cookies to flatten them to ½-inch thickness. Using a lightly floured fork or other metal utensil, press a pattern into the tops of the cookies. Bake, one sheet at a time, for 13 to 15 minutes, or until very lightly browned around the edges. Allow the cookies to cool to room temperature on the baking sheets.

Tempered Chocolate (Optional)

• Tempered chocolate is time sensitive and will firm up quickly once properly tempered, so make sure you have prepared all your tools and have the cookies you wish to dip or coat within reach. We are using the seeding method of tempering chocolate. It is the easiest way to temper at home. Set up a double boiler by first filling a medium pot with 2 to 3 inches of water and bringing it to a boil. Select the largest glass or metal bowl you have that will fit over your pot but won’t touch the water. Once the water has boiled, reduce the heat to maintain a low simmer and place the bowl over the pot. Add 2⅓ cups of the chocolate to the bowl, setting the remainder aside. It is important that no steam gets into the bowl. Any moisture can seize the chocolate and make it impossible to temper. Stir the chocolate frequently with a silicone spatula until it has all melted and reaches 125°F to 130°F (52°C to 55°C) on a candy thermometer. Do not heat the chocolate over 130°F (55°C).
• Once the melted chocolate has reached 125°F to 130°F (52°C to 55°C), remove it from the heat and place the bowl on a damp kitchen towel to keep it from shifting while you stir. Add most of the remaining chocolate, reserving about a quarter of it. Stir vigorously in one direction until all the seeding chocolate is melted. The goal is to have all the chocolate melted and the temperature reduced to 89°F (32°C).
• Check the temperature of your chocolate. If it is still above 93°F (34°C), add the reserved chocolate and stir vigorously in the same direction until all the seeding chocolate is melted. If your arm gets sore, switch hands but maintain the same direction while stirring.
• Check the temperature of your chocolate again. If it is still above 93°F (34°C), add the remaining 1 to 2 ounces (28 to 57 g) chocolate and stir vigorously in the same direction until all the seeding chocolate is melted. If the chocolate is still not at 89°F (32°C), continue to stir vigorously until it is.
• Once your chocolate is below 89°F (32°C), check your temper by drizzling chocolate over the back of a metal spoon or palette knife. Let sit for 3 to 4 minutes. The chocolate on the tester should harden and be glossy within 4 minutes. If your chocolate does not harden or is cloudy or streaky, stir as hard as you can for 60 to 120 seconds and test again.
• Drizzle the tops of the cookies with tempered milk chocolate.