Preheat the oven to 180 C/350 F/160 FAN/Gas 4 and Line 2 baking trays with baking parchment.
In a large bowl, cream together the butter and sugar until well combined, pale and soft.
Beat in the egg yolks thoroughly, one at a time.
Add the flour and lemon zest to the bowl and stir to combine the mixture.
Use your hands to bring the mixture together into a ball in the bowl.
Sprinkle a little flour on a work surface and knead the dough briefly.
Roll out the dough to half a centimetre or a quarter of an inch thick.
Use a cutter around 7.5 centimetres or 3 inch to cut 16 shapes
Bake the biscuits for 15 minutes until golden.
Leave the biscuits to cool on the trays for a couple of minutes then transfer to a rack to cool.
Notes
Disclaimer:The nutritional information provided is approximate and is calculated using online tools. Information can vary depending on various factors, but we have endeavoured to be as accurate as possible.