Preheat the oven to 180 °C.

Place the butter and flour in a food processor and whizz until combined.

Add the sugar and mix until it is crumbles.

Lightly spray the moulds with a non-stick cooking spray.

Press the mixture into the star moulds and place onto a lined baking tray. Sprinkle the nuts over the shortbread and bake for 9-12 minutes until golden brown.

Gently press the stars out of the moulds and allow to cool.

Dust lightly with icing sugar.