Jam cookies

Preheat the oven to 180°C and grease a few baking sheets with butter or non-stick spray.
Cream the butter or margarine, sugar, egg yolk and vanilla essence together until pale and fluffy.
Add the flour and salt and mix to form a stiff dough. (The dough will look dry, but carry on kneading until it comes together.)
Pinch off pieces and roll into balls.
Dip each ball in the whisked egg white before rolling in the nuts or coconut.
Arrange the balls on the baking sheets and make a hole in each.
Bake for 10 minutes or until pale brown.
Remove from the baking sheets and leave to cool.
Heat the jam until lukewarm and use to fill the holes in the cookies.