Preheat the oven to 180°C and line 2 baking trays with baking paper.

In a large bowl combine the butter and 1 cup of icing sugar.

Add in the flour, corn flour and vanilla and mix with your hands until well combined.

Knead together the mixture to form a soft dough.

Cover the dough with plastic wrap and allow it to stand for 10 to 15 minutes.

Turn the dough out onto a floured counter and roll out to about 1/2 cm thick.

Cut out the cookies with a round cookie cutter and place them on the lined baking tray.

Bake for about 10 – 12 minutes, remove from the oven and let them cool on a rack for 10 minutes.

Once completely cool, spread half the biscuits with dulce de leche and gently sandwich the biscuits together.

Sprinkle them with icing sugar and enjoy!