Swirled Citrus Butter Cookies

In a large bowl, cream together the softened butter, granulated sugar, vanilla extract, and kosher salt. Using an electric mixer, begin on low speed for approximately 30 seconds to combine, then increase to medium speed. Continue beating until the mixture is light, fluffy, and clings to the sides of the bowl, about 2-3 minutes. Scrape down the sides of the bowl as needed.

Add the egg white to the butter mixture and beat until fully incorporated, about 1 minute. Gradually add the flour, mixing on low speed until just combined, approximately 30 seconds. Increase the speed to medium and mix until the dough comes together into a cohesive ball, being careful not to overmix.

Divide the dough evenly into two separate bowls. To one portion, add the lime zest and matcha powder; mix thoroughly until the color is uniform. To the second portion, add the lemon zest and turmeric; mix until evenly colored. (Approx. 2-3 minutes per dough)

Shape each dough portion into a ball, then flatten slightly into a disc. Wrap each disc tightly in plastic wrap and chill in the refrigerator until firm and easy to handle, about 1 hour.

Preheat your oven to 350 degrees F (175 degrees C). Line a baking sheet with parchment paper for easy release and cleanup.

Remove the doughs from the refrigerator. Divide each dough portion into 16 equal pieces. On a lightly floured surface, roll each piece into a 5-inch rope. Take one green rope and one yellow rope, and twist them together. Coil the twisted rope into a spiral shape, tucking the ends underneath and pressing gently to seal. Place the formed cookie on the prepared baking sheet. Repeat with the remaining dough pieces, spacing the cookies about 1 inch apart. Sprinkle the tops of the cookies generously with coarse sugar.

Bake in the preheated oven until the edges of the cookies are lightly golden brown, approximately 10-12 minutes. Remove from the oven and let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely. (Cooling: 30 minutes)

Store the cooled cookies in an airtight container at room temperature for up to 3 days, or freeze for up to 3 months for longer storage.