Sift the
flour, ginger, cinnamon, cloves, baking
soda, and salt into a medium bowl. Mix the
butter, brown sugar, and molasses in a
medium saucepan over low heat.
Cook,
stirring constantly, until the sugar has
dissolved completely. Remove from the heat
and mix in the dry ingredients and lemon
zest to form a stiff dough.
Divide the
dough in half. Press the dough into two
disks, wrap in plastic wrap, and refrigerate
for 1 hour.
Preheat the oven to
350°F/180°C/gas 4. Butter two cookie sheets. Roll half the dough out on a lightly floured
surface to 10-inch (25-cm) square. Cut
into 2-inch (5-cm) squares.
Use a spatula
to transfer the cookies to the prepared
cookie sheets, placing them 1 inch (2.5 cm)
apart. Prick all over with a fork.
Repeat with the remaining dough. Sprinkle
with the granulated sugar. Bake for 5-7
minutes, or until lightly browned. Transfer to racks and let cool completely.