- Preheat oven to 350F. Beat the butter in a medium mixing bowl with an electric mixer on medium to high speed for 30 seconds. Add 1/4 cup granulated sugar until combined. Beat until combined, scraping sides of bowl occasionally. Beat in thyme, lemon peel, lemon juice, and cardamom. Beat in as much of the flour as you can with the mixer. Stir in any remaining flour with a wooden spoon. Knead until smooth; form mixture into a ball.
- Divide dough into three equal portions. Roll each portion into a 6x4 1/2-inch rectangle (about 1/4 inch thick) on a lightly floured surface. Cut dough into 1 1/2-inch squares with a scalloped-edge pastry wheel. Sprinkle cutouts with coarse sugar. Place cutouts on ungreased cookie sheets.
- Bake in preheated oven for 12 to 15 minutes or until edges are just lightly brown. Transfer to wire racks and let cool. Makes 36 cookies.
From the Test Kitchen
Place cookies in layers separated by pieces of waxed paper in an airtight container; cover. Store at room temperature for up to 3 days or freeze for up to 3 months. Thaw cookies, if frozen, before serving.