Ingredients
Preparation
Step 1
Sift the flour and cocoa powder together. Add the salt.
Step 2
In the stand mixer fitted with the paddle attachment, cream the butter and confectioners’ sugar at medium-high speed 3 to 4 minutes, until the mixture is light and fluffy. Add the yolk and coffee extract, and beat until fluffy again. Add the dry ingredients slowly, and mix at low speed. The dough should be crumbly and not quite bound together. Right before the dough comes together, add the chocolate shards and mix for a second, just to incorporate.
Step 3
Shape the dough into logs about 1 1/2 inches in diameter. Roll the logs in the granulated sugar, and wrap each one in plastic. Refrigerate until very cold and firm.
Step 4
Preheat the oven to 350°F.
Step 5
Slice the dough into 1/4-inch-thick rounds, and place them 1/2 inch apart on a parchment-lined baking sheet. Bake 12 to 15 minutes, until set. (They will seem a little underbaked because of the chocolate shards.)
