Sift the
flour, cocoa, and salt into a large bowl. Use a
pastry blender to cut in the butter until the
mixture resembles fine crumbs.
Stir in the
sugar and vanilla. Add the milk to form a stiff
dough. Form the dough into a log 1 inch (2.5 cm)
in diameter, wrap in plastic wrap, and
refrigerate for 30 minutes.
Preheat the
oven to 400°F/200°C/gas 6. Butter a cookie
sheet. Slice the dough into 2inch (5-cm) lengths
and place 1 inch (2.5 cm) apart on the prepared
cookie sheet.
Bake for
20-25 minutes, or until lightly browned and firm
to the touch. Transfer to racks to cool.
Frosting: Mix
the cocoa with the water until smooth. Beat the
butter in a medium bowl until creamy.
Beat the
confectioners' sugar and the cocoa mixture until
smooth. Use a thin metal spatula to spread the
tops of the cookies with the frosting.
Draw the
tines of a fork across the frosting to resemble
the bark of a log.