Method

• 1.
  In a stand mixer fitted with the paddle attachment, cream together the butter, sugar and cardamom on medium speed for 5 minutes, or until pale and creamy.
• 2.
  Sift together the flour, cornflour and ½ tsp fine salt into a bowl. Add the flour mixture to the creamed butter mixture in three batches, beating slowly between each addition. After the third addition, mix until just combined.
• 3.
  Tip the dough out onto a lightly floured bench and gently knead, just to bring it all together. Wrap the dough in plastic wrap and rest it in the fridge for at least 1 hour before using, or preferably overnight.
• 4.
  When you’re ready to bake, remove dough from the fridge 20-30 minutes before rolling. Preheat oven to 180°C/160°C fan-forced. Line a baking tray with baking paper.
• 5.
  Unwrap dough and place on a lightly floured bench. Use a rolling pin to roll it into a rectangle 20cm x 15cm x 1.5 m thick. Use a knife to cut dough into 2cm x 10cm fingers. Place shortbread fingers spaced out evenly onto the prepared tray. Sprinkle with extra sugar and bake for 15 minutes. Rotate the tray in the oven and bake for another 2-5 minutes, until edges are just starting to colour. Cool on a wire rack before serving.
• 6.
  Serve warm or at room temperature, sprinkled with extra cardamom.