| Preparation | Resting | Cooking | Start to finish |
|---|---|---|---|
| 35 min. | 2 hours 10 min. | 15 min. | 2 hours 55 min. |
| 1 | Separate the egg whites from the yolks at 1 egg. In the bowl of a mixer, combine 85 g icing sugar, 170 g butter, 15 g powdered cocoa, and 2 pinches fine (or table) salt. | ![]() |
| 2 | Turn on the mixer at a medium-low speed until the mixture is creamy and chocolatey. Turn off the mixer, add the egg yolk and 210 g flour, then turn it back on at low speed... | ![]() |
| 3 | ...until the mixture is smooth. | ![]() |
| 4 | Pour the dough onto your work surface, and shape it into a large ball. | ![]() |
| 5 | Cut the ball in half, then roll each half into a cylindrical log about 3 cm (1.2 inch) in diameter. This isn't easy because the dough is very soft, but you can refine the shape in the next step. | ![]() |
| 6 | Wrap each cylinder, and once you've done that, it'll be easier to roll them more carefully. Put them in the fridge for 1 to 2 hours, or even overnight. | ![]() |
| 7 | After that time has elapsed, preheat your oven to 160°C (320°F). Remove the plastic wrap from one of the cylinders—which has become quite hard after being in the fridge—and use a pastry brush to coat its entire surface with egg white. | ![]() |
| 8 | Then sprinkle it with 4 tablespoons granulated sugar. | ![]() |
| 9 | Then cut it into slices about 1 cm (0.4 inches) thick. The thin layer of granulated sugar on the slice gives it a shiny appearance known as a “diamond.” | ![]() |
| 10 | Do the same for the other cylinder, and place the slices on a sheet of parchment paper laid out on a baking sheet. | ![]() |
| 11 | Bake for 12 minutes. | ![]() |
| 12 | Let them cool on a wire rack. Your melt-in-your-mouth chocolate shortbread cookies are ready to enjoy. | ![]() |