6 ounces dark chocolate, chopped or dark chocolate chips (1-2 cups)
½ teaspoon shortening
Add the butter to a bowl of an electric mixer. Using the paddle attachment, mix butter on medium speed for 30 seconds. Add sugar and salt and mix until thoroughly combined. Then, add in egg and cocoa powder. Use a spatula to clean off sides of bowl and continue to mix all ingredients until once again combined. Add in the flour in ½ cup increments and mix until incorporated.
Lay out 2 large sheet of plastic wrap. Divide dough in half and place on top of each sheet of plastic wrap. Wrap the plastic wrap around dough and roll into an 11-inch log. Repeat for other half of dough. Refrigerate the two dough logs for 1 to 2 hours.
Preheat the oven to 375 degrees Fahrenheit and prepare baking sheets with parchment paper. Cut the dough into thin slices (about ¼".) I was able to get about 25 cookies from each log, so there will be ~50 cookies in total. Bake for 6-8 minutes or until cookie tops are firm. Remove from oven and let cookies cool on a wire rack.
Meanwhile, melt the chocolate and shortening together in the microwave in 30-second increments (I used a Pyrex glass.) Stir after each increment until melted. Place cooled cookies on wax paper and use a spoon to drizzle melted chocolate on top. Before chocolate hardens, sprinkle on chopped hazelnuts. Allow chocolate to set and then serve, store in an airtight container, or freeze.
Recipe by 2 Sisters 2 Cities at http://www.2sisters2cities.com/2013/12/7-chocolate-hazelnut-coins/