Beat butter and ½ cup of sugar on medium speed until light and fluffy. I used my seven speed handheld mixer on speed 5. It took about 3-5 minutes.
Add flour and mix until the mixture is crumbly. I used my mixer but can use clean hand by rubbing the flour into butter mixture until crumb like.
Transfer the dough mixture to a clean surface and continue rubbing by hand.
Lightly knead the mixture to form a dough.
Shape the dough into a rectangular log.
Sprinkle 2-3 tablespoon of sugar on a wax or parchment paper. Roll the dough in it.
Once the dough log is coated with sugar, transfer to a plastic wrap, wrap the dough log.
Refrigerate for about 30 minutes until the dough is firm.
Preheat the oven to 325F.
Slice the dough into ¼” thick squares and place on a cookie sheet. Place the cookies at least 1” apart as the cookies spread when baking.
Bake in a preheated oven for 18-20 minutes or until light golden. I baked on the middle rack for 20 minutes. If the squares are not of even thickness, keep an eye on thin cookies after 18 minutes into baking.
Cool the cookies for 5 minutes on the sheet, transfer to cooling rack and let cool completely before storing in an airtight container.