DIAMOND CARDAMOM SPARKLE COOKIES

Steps:

• Dough:
• Beat granulated sugar and butter in the bowl of a stand mixer fitted with a paddle attachment on medium speed until pale and fluffy, about 5 minutes. Beat in egg and lemon zest, scraping down bowl with a rubber spatula as needed.
• Sift flour, cinnamon, and nutmeg into a medium bowl. Pulse cardamom and peppercorns in a spice mill or grind in a mortar and pestle until the consistency of coarsely ground coffee-be careful not to grind too finely. (Alternatively, you can wrap in a kitchen towel and pound with a rolling pin.) Whisk cardamom, pepper, and salt into dry ingredients. With mixer on medium-low speed, gradually add to stand mixer bowl in 2-3 additions, scraping down sides and bottom of bowl between additions; beat just until combined, about 1 minute (be careful not to overmix).
• Divide dough in half and flatten each into a 4½"-wide square, about 1" thick. Wrap each square tightly in plastic and chill at least 1 hour before using.
• Do ahead: Dough can be made 3 days ahead. Keep chilled, or freeze up to 1 month. If freezing, thaw in fridge overnight before using.
• Glaze and assembly:
• Let dough sit at room temperature 20 minutes. Place 1 square of dough on a large sheet of parchment paper; unwrap and arrange plastic wrap over dough to prevent sticking (and eliminate the need for flouring). Roll out to ¼" thick and chill in the freezer until firm, at least 30 minutes.
• Remove and reserve plastic wrap. Punch out cookies with cutter and transfer right away, while dough is still cold, to a parchment-lined flexible cutting board or parchment-lined baking sheet, arranging in a single layer and placing close together for efficiency. Stack, layering with sheets of parchment in between, if needed. Freeze all pieces until ready to bake, at least 15 minutes. Well-wrapped cookies can be frozen up to 1 week. (If you do not have a diamond cookie cutter, you can roll the dough out to a ¼"-thick square and cut dough into 2"-wide strips. Cut strips on a 60° angle 2" apart to create diamonds.)
• Meanwhile, pat together scraps and roll out between leftover parchment paper and reserved plastic wrap. Repeat entire process with remaining square of dough.
• Place racks in middle and lower third of oven; preheat to 325°F. Arrange 9 frozen cookies each on 2 parchment-lined baking sheets, spacing about 1" apart. Bake cookies, rotating baking sheets front to back and top to bottom halfway through, until edges are barely golden, about 15 minutes. Let cool 5 minutes, then transfer to a wire rack and let cool completely. They should be crisp but chewy. Bake remaining cookies. (If you'd like sharp defined edges and are serving cookies the same day, trim them as soon as they come out of the oven. Don't trim if you aren't eating them directly. They will harden faster.)
• While the cookies are cooling, whisk powdered sugar and corn syrup in a medium bowl, adding 1 Tbsp. lemon juice at a time, until combined. Glaze should be thick but pourable (you can thin with a bit of water if needed). Transfer 1 Tbsp. glaze to a ramekin or small bowl. Barely dip the tip of a toothpick into food coloring and mix into glaze in ramekin. Dip a fresh toothpick into ramekin with teal glaze and add to glaze in bowl; mix well to tint. Repeat process, gradually adding color until you have a soft shade of celadon. This technique is helpful when you want to create pale, subtle colors and will prevent you from oversaturating the entire quantity of glaze.
• Combine almonds and a few drops of edible gold paint (if using) in a small bowl and toss until almonds are well coated. Spread out on a plate and let dry, about 15 minutes.
• Using a small offset spatula or spoon, add a dollop of glaze on to one side of a cookie. Spread a thin layer of glaze over half of the cookie, making a straight edge along the center for a graphic look. Wipe off any excess glaze and clean up edges with your finger (keep a damp kitchen towel nearby to keep fingers clean). Transfer to a wire rack set inside a rimmed baking sheet. Sprinkle gold almonds and chunky sugars over glaze (you want to do this while it is still wet). Repeat with remaining cookies, changing the direction or even the geometric shape of the glazed area if desired. Let cookies sit until glaze is set before serving, about 3 hours. Drying time may vary depending on how thick your glaze is and the humidity.
• Do ahead: Glaze can be made 3 days ahead; transfer to an airtight container. Cover and chill. Almonds can be coated 5 days ahead; store airtight at room temperature. Cookies can be decorated 4 days ahead; store airtight at room temperature.