1
["Dissolve espresso in the vanilla. Sift together the flour, cocoa, salt, and baking soda. Cream together butter and sugars until light in color (at least five minutes on high speed in a stand mixer). Mix in egg white. On low speed, slowly add in dry ingredients until just incorporated. Finish mixing by hand, kneading as little as possible, until the dough is smooth.", "Form dough into two roughly equal logs, about 2"" diameter. Wrap each log tightly in parchment or wax paper, and refrigerate at least 1 hour until firm. Seal each log in airtight container; freeze up to 1 month (defrost overnight in the refrigerator) or store in the refrigerator up to 1 week.", "Preheat oven to 350F. Slice log into 1/4"" rounds; arrange on parchment-lined heavy baking sheets.", "Bake cookies in the middle of the oven until cracked and nearly firm, about 13-15 minutes. Transfer to racks and let cool completely."]
