Cream together diced butter, sifted powdered sugar, vanilla extract, orange zest, and a pinch of salt. You can do this with an electric mixer or food processor.
Grate the chocolate. In other bowl mix sifted flour, cocoa powder, cornstarch, baking powder, and ground cardamom, and then add grated chocolate.
Add dry ingredients to a bowl of creamed butter and sugar and slowly mix together until combined. Transfer the dough to the working surface and use your hands for forming the dough into a log. For bigger cookies (like mine) make a log that is 5 cm in diameter. Wrap it in plastic foil and put it in a fridge for at least 2 hours or until firm enough so it can be cut with the knife. You can also even leave it overnight.
When you're ready to bake cookies, preheat your oven to 170°C/338°F. Take the log from the refrigerator and cut it with a serrated knife into 1 cm thick rounds. Transfer them to the baking sheet in which you've previously put baking paper. Leave some space in between because they will spread.
Bake the cookies for 12-14 minutes. They shouldn't be too hard when you take them out of the oven but also not too soft. They will harden when they cool completely. After they have chilled a little bit, transfer them to a cooling rack to cool completely. Decorate with melted dark chocolate and Fleur de sel.
Nutritional information provided is an estimate based on ingredients
data and should be used for informational purposes only. Actual nutritional content may vary based on factors such
as portion size, preparation methods and ingredients used.