1. Preheat the oven to 170C(fan oven 150C), gas mark 3. Using an electric mixer, beat together the butter and sugar until pale and creamy.
2. Stir in the orange zest, egg yolks, ground almonds, dried cranberries and flour. Mix well together, then roll into walnut-sized balls.
3. Place on a baking sheet, spaced well apart, and flatten each ball slightly with your hand. Brush with milk, then bake for 18-20 minutes until golden.
4. After removing from the oven, leave the cookies to firm up on the baking sheet for 5 minutes before transferring to a wire rack to cool. Store in an airtight container.
Tips: These scrumptious cookies really deserve their name - they're crunchy with a lovely buttery flavour and little nuggets of chewy dried cranberry.