In the mixing bowl on medium/low speed beat the sugar and butter until creamy. Then beat in the egg and yolk, add the juice and zest and beat to combine.
Add half the flour and salt and combine, then add the remaining flour and combine with a wooden spoon or spatula. (or if using a stand up mixer and flat spatula or food processor, then continue to combine with this, but just until combined).
Move the mixture to a lightly floured flat surface and quickly knead to form a compact dough. Form into a ball, wrap it in plastic wrap and refrigerate for one hour.
Pre-heat oven to 350F (180C). Line 1-2 baking sheets with parchment paper.
Roll the dough into ¼ inch thickness and cut into desired shapes. Place on a prepared cookie sheet, sprinkle the cookies with the sugar, while the oven is preheating refrigerate the cookies, then bake 8-10 minutes or until the edges start to turn golden brown. Let cool on cookie sheet then move to a wire rack to cool completely, enjoy.
Notes
The dough can be made and stored wrapped well in plastic wrap in the refrigerator. It will keep for up to three days in the fridge. It can also be frozen in a freezer safe bag or container for up to 9 months. To thaw the dough place it in the fridge for a few hours and let it thaw gradually.The cookies should be stored in an air tight container and kept at room temperature. They will keep for up to three days. Stored in the fridge in an air tight container they will keep for up to a week.The cookies should be stored in an air tight freezer safe bag or container. They will keep up to three months.