125g butter, chopped, softened
2 tsp vanilla bean paste
1⁄4 cup caster sugar
1 cup plain flour
1⁄4 cup rice flour
Preheat oven to 140°C. Put butter and vanilla in the bowl of an electric mixer and, using paddle attachment, beat on medium until combined. Add sugar and beat again for 1 minute. Increase to high and beat for a further 2 minutes or until light and creamy.
Sift flours over butter mixture and beat on low until a crumbly dough forms. Form dough into a ball.
Push dough into a 22 x 15cm Festive Pan. Using back of a spoon, push down dough firmly and smooth surface. To maximise the indentation, divide dough into 6 portions and, starting from centre of each square, push firmly with fingertips, spreading dough. If you are making batches, wash and cool tin completely between batches. You can put it in the fridge to do this more quickly.
Bake for 40 minutes. Remove from oven and set aside for 2 minutes. Using back of spoon, smooth surface again, using a little pressure. Set aside for 15 minutes to cool slightly.
While still warm, turn out onto a chopping board. Cut into 6 pieces. Set aside to cool. Serve.
To top with chocolate
Spread 100g melted dark chocolate melts into base of cleaned and cooled pan. Put uncut cooked shortbread on top, imprint side down. Freeze for 30 minutes or until chocolate has set then turn out, cut and serve.