Place all the ingredients in a mixer or blender. Add the butter first, followed by icing sugar, and cornstarch and salt.
Lastly, add the cake flour on top. At this point, I remove the mixture into another bowl and slowly add the cake flour to reach the desired consistency of the dough.
If you prefer using the mixer or food processor, follow the next step.
Mix until the ingredients are well combined and clear from the side of the mixing bowl.
Place small balls or pipe cookies onto baking paper on baking tray.
Bake at 180 degrees celcius for 12-15 minutes.
Once baked, leave to cool completely before decorating with melted chocolate and/nuts.