Method

• 1.
  Preheat oven to 200°C. Grease 3 baking trays and line with baking paper. Beat butter, sugar and vanilla in the bowl of stand mixer fitted with the paddle attachment until light and fluffy. Add the egg, beating until just combined. Add the flour, beating until the mixture is combined and a soft dough forms.
• 2.
  Shape the dough into a disc and enclose in plastic wrap. Refrigerate for 30 minutes, to rest. Roll out the dough between 2 sheets of baking paper until 4-5mm in thickness. Using a 6cm cutter, cut into rounds. Place on prepared trays. Bake for 6-7 minutes or until biscuits are cooked. Set aside to cool completely on a wire rack.
• 3.
  Spoon 1/2 tsp dulce de leche onto the centre of half of the biscuits. Top with remaining biscuits, pressing together until the filling almost oozes out.
• 4.
  Dust with icing sugar to serve.