Lemon curd biscuits

For ➋x➓ cookies 
125 g butter, cold 
225 g flour 
125 g sugar 
1 egg zest of 1 lemon 
100 g lemon curd 
salt 
powdered sugar 

Cut the butter into cubes. Mix with flour, sugar, egg, a pinch of salt and the zest of a lemon in the bowl of the food processor. Knead it into a firm dough. If the dough is still too dry, add 1 tbs of ice-cold water if necessary. Wrap the dough in cling film. Let it rest for at least 30 m in the refrigerator. Preheat the oven to 170 ° C. Remove the dough from the fridge and form balls the size of a 2 euro coin. Place them on a baking tray lined with parchment paper. Press a hole in the dough with your thumb or with a spoon. Divide 1 ts lemon curd over the hole. 
Bake the lemon curd cookies in the oven in about 15-20 m. 
Let them cool on a cooling grid. 
Sprinkle them with icing sugar when they have cooled down. 
Store the lemon curd cookies in an airtight container.