Ingredients (serves 6 people)

• 500g butter, softened
• 500ml icing sugar, plus extra for dusting
• 500ml gluten-free flour
• 100ml corn flour
• Castor sugar, for dusting

Directions

1. Beat the butter and icing sugar together until smooth.

2. Sift the dry ingredients together and add to the butter mixture. Mix well. Knead lightly until a soft dough forms. Cover in cling film and place in the fridge for 15 minutes.

3. Heat the oven to160°C. Remove from the fridge and knead lightly to soften the dough. Press into an ungreased 20 x 30cm baking tin and prick all over with a fork.

4. Bake for 30 minutes. Reduce the temperature to 140°C and bake the shortbread for another 45 minutes or until it is a light golden brown colour.

5. Remove from the oven and cool for two minutes. Cut into fingers or squares and dust with castor sugar. Leave to cool slightly. Remove from the baking tin and cool on a wire rack. Dust lightly with icing sugar.