Soak the candied
peel in the orange liqueur for 1 hour.Drain, reserving
the liqueur.
Preheat the oven
to 375°F/190°C/gas 5.
Line two
cookie sheets with parchment paper.
Sift the flour,
baking powder, and salt into a medium bowl.Beat the butter
and sugar in a large bowl with an electric mixer at
high speed until creamy. Add the lemon extract.
With mixer at
high speed, beat in the egg whites and the reserved
orange liqueur. Mix in the dry ingredients. Fit a
pastry bag with a 1/2-inch (1-cm) plain tip.
Fill
the pastry bag, twist the opening tightly closed,
and squeeze out 1 1/2-inch (4-cm) mounds, spacing 2
inches (5 cm) apart on the prepared cookie sheets.
Lightly press a
piece of candied peel into the top of each cookie.
Bake for 8-10
minutes, or until
golden brown.
Cool on the sheets until the cookies
firm slightly. Transfer to racks
and let cool completely.