Ingredients

1 3/4 cup flour

1/2 cup unsweetned cocoa

pinch salt

1 stick plus 2 tbs unsalted butter

3/4 cup plus 2 tbs powdered sugar

1 tsp vanilla

1 large egg white

1/2 cup sugar

2 tbs cold milk

Preparation

  1. In food processor pulse flour, cocoa, salt. Add butter and process until sandy, 3 min. Add powdered sugar, milk, vanilla and process till firm dough forms transfer dough to 2 sheets of plastic wrap, form 2 7-inch logs about 1 1/2 inch thick, wrap in plastic. Refrigerate 4 hours
  2. Preheat oven 350 and position racks in the upper and lower thirds. Line 2 large baking sheets with parchment paper. Beat egg white in small bowl. Sprinkle granulated sugar in a 7 inch square of parchment paper. Brush the logs with egg white and roll in sugar pressing to adhere. Cut into 1/4 inch pieces. Bake for 20 min