Cream together the butter, sugar and egg yolks

Add the flour a little at a time, until a soft dough forms

If the dough is soft, stick it in the fridge for 15mins or so

I didn't have to, so hopefully you don't have to either!

Roll the dough into 1 inch balls and place the balls 2 inch apart on a cookie sheet

Using your finger make a well in each cookie

Fill the hole with 1/2 teaspoon of preserves - I went with some Apple and Rhubarb preserve

Bake for 8-10 mins until it is golden brown

I would suggest lingering by the oven, cause they bake quite fast and you don't want them to burn!

Cool on wire racks before biting into one

Store in an air tight container

Dusting some icing sugar on this will make it look pretty too