- In a bowl, combine flour, cocoa powder and salt. Set aside.
- In another bowl, cream butter with sugar. Add egg and mix thoroughly. At low speed or with a wooden spoon, add dry ingredients. Shape into a disc with your hands and cover in plastic wrap. Refrigerate for 1 hour.
- With the rack in the middle position, preheat the oven to 180 °C (350 °F). Line a baking sheet with parchment paper or a silicone mat.
- On a lightly floured work surface or between two sheets of parchment paper, roll out dough into a 5-mm (¼-inch) thick sheet. With a 6-cm (2 ¼-inch) round cookie cutter (or other), cut cookies, reusing scraps. Place on the baking sheet, spacing them evenly. Bake one sheet at a time, for about 12 minutes or until edges of cookies are crisp (the cookie centre will still be soft, but will firm upon cooling). Let cool completely on the baking sheet. Decorate.