Prep Nutella balls by dropping teaspoon dollops on a silicone mat or lined baking sheet and freeze until hard.
With a stand or hand mixer; cream the butter, powdered sugar and vanilla essence until creamy. Scraping the sides and bottom of the bowl.
Sift in flour, salt and corn flour.
Mix until all ingredients are well incorporated.
Wrap dough in cling wrap and chill in the refrigerator for one hour.
Break off teaspoon sizes of the dough, placing the Nutella in the middle of each, making sure the Nutella is completely covered with dough.
Form balls and place on a lined baking sheet - spreading it out.
Chill in the refrigerator for another 30 minutes.
Just before taking the cookie balls out of the refrigerator, preheat the oven to 180°C.
Slightly press down each ball and bake for 10 - 12 minutes until golden.
Allow to cool.
Place chocolate in a microwave safe bowl and heat at 30 second intervals until melted. Drizzle over shortbread cookies.
