This is a recipe for egg-free "Devil's Diamant Chocolat" taught by a professional baker. By using 70% cocoa dark chocolate and fleur de sel (salt), it results in an addictive crunchy texture that will make you want to eat it again and again. It's packed with tips to ensure success, from sifting the dry ingredients twice for even mixing, to thoroughly mixing the butter and sugar, to chilling and firming the dough, and key points for baking. You can easily make a rich and profound baked good that chocolate lovers will adore.