Step 1

Preheat oven to 200C/180C fan forced. Line a baking tray with baking paper. Place a pastry sheet on tray. Prick well with a fork. Top with a sheet of baking paper and a second baking tray. Bake for 15-20 minutes or until crisp and golden. Cool completely on a wire rack. Repeat with remaining pastry.

Step 2

Line base and sides of a 23cm (base measurement) square cake pan with baking paper, allowing all 4 sides to overhang.

Step 3

Whisk cornflour, yolks and milk in a bowl. stir cream, sugar, butter, vanilla and extra milk in a saucepan over medium heat until sugar dissolves and butter melts. Slowly add cream mixture to egg mixture, whisking constantly until smooth. transfer mixture to saucepan. Cook over medium heat, whisking constantly, for 5 minutes or until mixture boils and thickens. Divide among 2 bowls. Add chocolate to 1 bowl. Stir until combined.

Step 4

Place 1 piece of pastry in prepared pan, trimming to fit. Spread chocolate custard over pastry. Top with another piece of pastry. Spread with vanilla custard. Top with remaining pastry, pressing down gently. cover. Place in fridge for 4 hours or until set.

Step 5

Carefully lift slice out of pan. Use a sharp twist serrated knife to cut into 6 pieces. Dust well with icing sugar. Heat a thick metal skewer over a flame until very hot and glowing red. Working quickly but carefully, hold ends of skewer with an oven glove and press onto icing sugar to caramelise the top in a crisscross, reheating skewer. Decorate with chocolate curls.