Preheat the oven to 150°C (300°F), Gas Mark 2.
Make the pastry by mixing all the ingredients to form a dough. Leave it to rest while you make the filling.
Mix all the ingredients for the filling and form into balls the size of a hazelnut.
Form the pastry into balls the size of a walnut. Press a ball of filling into each one, close the pastry around it, then fashion it into the shape of a crescent.
Place on an oiled baking sheet and cook for 15 minutes. Remove from the oven and dredge each crescent through the icing sugar to coat on all sides.