- In the lemon shortbread cookie recipe, replace the lemon juice with the same amount of limoncello.
- Form the dough into two logs each 1 1/2 inches (4 cm) in diameter. Cover in plastic wrap and refrigerate for 1 hour.
- On a work surface, cut the logs of dough into ½-inch (1 cm) slices. Arrange on the baking sheets.
- Bake one sheet at a time for 12 minutes or until the bottoms and edges of the cookies are slightly golden. Let cool completely on the baking sheet, about 1 hour.
Candied Lemon Peel
- Meanwhile, on a work surface, cut long, thin strips of lemon peel. Set aside.
- In a 4-cup (1 litre) capacity glass bowl, combine the water, sugar and corn syrup. Cook in the microwave oven for 3 to 4 minutes or until the sugar has dissolved. Add the strips of lemon peel and mix together. Cook for another 6 minutes in the microwave oven, until the lemon peel is slightly translucent. Let cool.
- Cover and refrigerate for 30 minutes or until completely chilled. The candied lemon peel with keep for 2 weeks in an airtight container in the refrigerator. Drain on a paper towel before using to decorate the cookies. The syrup used for the lemon peels can be used to flavour water or cocktails.
- In a bowl, whisk together all of the ingredients.
- Dip the tops of the cookies in the icing. Decorate with a few pieces of candied lemon peel. Let sit until the icing has set. The cookies will keep for 1 week in an airtight container at room temperature.