Directions

1. 1. Preheat the oven to 400°F/200°C/gas 6.
2. 2. Butter a cookie sheet.
3. 3. Use a pencil and ruler to draw a 12 x 8-inch (30 x 20-cm) rectangle on a sheet of parchment paper.
4. 4. Draw triangles, points facing inward, at each end of the rectangle to resemble a double-edged bowtie. Cut out the template.
5. 5. Place the template on the prepared cookie sheet.
6. 6. Beat the butter and confectioners' sugar in a large bowl with an electric mixer at high speed until creamy.
7. 7. Stir in the e whites, followed by the flour and salt.
8. 8. If the mixture separates, place over barely simmering water and mix.
9. 9. Set aside 2 tablespoons of the mixture. Stir the cocoa into the remaining batter.
10. 10. Use a thin metal spatula to spread a small amount of plain cookie batter around the inside edge of the template to form a border.
11. 11. Spread the remaining plain batter in the center of the template.
12. 12. Spoon the cocoa batter into a small plastic freezer bag. Cut off the corner and pipe over the edges.
13. 13. Bake for 8-10 minutes, or until just golden.
14. 14. Use a spatula to loosen the edges and transfer to a rack to cool completely.