Mix all the ingredients together, apart from the walnuts and knead into a dough.

Shape the dough into a log and wrap it in plastic wrap. Refrigerate for at least 2 hours.

Cut the log into 80 mm – ⅓″ slices. Top each cookie with some crushed walnuts (press them down slightly so they don’t fall off).

Bake the cookies on a baking sheet lined with baking paper at 180°C – 355°F for 10-15 minutes, or until just golden around the edges.

When cooked, let them cool down on the baking sheet for 5 minutes, then transfer them to a wire rack to cool down completely.

Store them in an air-tight container for up to 3 days.