These little cookies are great if you have trimmings of plain sablée and chocolate sablée left over. They indeed have a marbled appearance and combine the flavors of butter and chocolate in a nutty crumbly cookie.
Unless you are using nonstick pans, line 2 sheet pans with parchment paper or silicone baking mats. Squeeze each dough into rough strips and bunch the strips together. Use your hands to roll the mixed doughs into a cylinder, slightly less than