*I use salted butter, if you use unsalted then increase the salt to 1/4 teaspoon. Be sure to use a good quality butter, apparently this year 2022, store brand butter quality is not what it used to be. Less fat could mean a dry not so tasty cookie.
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 with a wooden spoon or spatula combine to form a dough (the dough will be a little sticky, if the dough is too sticky then add 1-2 tablespoons of flour).
Transfer the dough to a large piece of parchment paper and roll the dough into a log approximately 1 1/2 inches (4cm) wide. Wrap the dough in the parchment paper and refrigerate for one hour.
Remove the dough from the fridge and cut into 1/2 inch (1.3 cm) 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 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 either dusted with powdered sugar or spread with a lemon glaze. Enjoy!
In a small bowl whisk together the lemon juice, powdered sugar and zest until smooth.
To keep cookies from spreading it helps to chill the dough before baking and the percentage of protein in the flour is a major culprit of flat cookies. I would advise that your flour has a percentage of at least 11% or even higher if possible.If the cookies are unglazed then they should be stored in an airtight container at room temperature, they will last up to 5-6 days. If glazed then they should keep stored in an airtight container, in a single layer for about 3-4 days.If your home is warm then I would advise refrigerating in an airtight container. If the cookies are refrigerated they will last up to 7 days.You can always freeze them in either a freezer bag or an airtight container, they will keep for up to 4 weeks.The unbaked cookie dough will last 2-3 days in the fridge and two months in the freezer. Wrap the dough well in plastic wrap and place in an air tight bag.