Preparation / Directions:
1. In the bowl of an electric mixer fitted with the paddle attachment, cream butter and sugar until light and fluffy, 3 to 4 minutes. Add egg; beat until just blended. Add citrus zests, lime juice, and almond extract.
2. With the mixer on low speed, add the flour and cornmeal. Continue beating until well blended. Transfer the dough to a piece of plastic wrap. Shape the dough into a disk, wrap, and chill until firm, about 1 hour.
3. Heat oven to 350 degrees. Line two baking sheets with Silpat nonstick baking mats. Using a 1 1/4-inch ice-cream scoop, form balls from chilled dough. Place balls on prepared sheets, spaced about 3 inches apart. Dip bottom of a medium drinking glass into a bowl filled with cornmeal. Flatten balls with the bottom of glass until dough is about 1/4-inch thick.
4. Bake cookies until crisp and light golden brown around the edges, 14 to 16 minutes. Transfer baking sheets to a wire rack, and let the cookies cool completely.
5. Place a wire rack on top of a piece of parchment paper. Pour the lime glaze over the cooled cookies, allowing the excess to drip off the edges. Let glaze set. Store cookies in an airtight container up to 1 week.
Makes about 2 dozen.
Lime Glaze: Sift confectioners' sugar into a medium bowl. Add lime juice; stir until smooth. Stir in the lime zest. Use the glaze immediately.
Note from Martha: Inspired by Southwestern and Italian desserts, these cookies combine the unusual flavors and textures of citrus zest, and crunchy, stone-ground cornmeal. For the best flavor, use freshly squeezed lime juice and freshly grated zest; don't substitute bottled juice or use juice or zest that has been stored in the refrigerator. It's also important to use pure almond extract rather than artificial flavoring, though you can substitute vanilla extract if you don't care for the taste of almond. Though the instructions below call for mixing the cookie dough in the bowl of an electric mixer, you can do the whole job the old-fashioned way—in a bowl, with a wooden spoon—if you