In a medium bowl whisk together the flour, cornstarch, zest and salt.

In a large bowl, beat on medium speed the butter and sugar until fluffy, 3-5 minutes. Then add half the flour and the lemon juice beat to combine. Then add the remaining flour and combine to form a dough.

Transfer the dough to a large piece of parchment paper and roll the dough into a log approximately 1 ½ inches wide. Wrap the dough in parchment paper and refrigerate for one hour.

Remove the dough from the fridge and cut into ½ inch slices. Place the slices on a large cookie sheet lined with parchment paper and refrigerate for 20 minutes.

Pre-heat oven to 320F (160C).

Bake the cookies for 5 minutes, then raise the oven temperature to 350F (180C) and continue to bake for 9-10 minutes. The cookies should be light gold in colour.

Remove from the oven and let the cookies sit on the cookie sheet for about 5 minutes, then move to a wire rack to cool completely. The cookies can be dusted with powdered sugar or spread with a lemon glaze.

In a small bowl whisk together the lemon juice, powdered sugar and zest until smooth.