• 3 sheets frozen butter puff pastry, thawed (see note)

Yuzu Vanilla Custard

• 150g (2/3 cup) caster sugar
• 100g (2/3 cup) cornflour
• 810ml (3¼ cups) milk
• 80ml (1/3 cup) yuzu juice
• Scraped seeds of 1 vanilla bean
• 2 egg yolks
• 40g butter, softened

Yuzu Icing

• 240g icing sugar mixture, sifted
• 2 tbsp melted butter
• 2 tbsp yuzu juice, strained, at room temperature

1. Preheat oven to 200˚C. Place puff on oven trays lined with baking paper, top with another sheet of baking paper followed by another tray on top. Prick all over with a fork, and bake, in batches if necessary, until golden (15-20 minutes). Cool on a wire rack. Using a serrated knife, trim edges so pastry fits into a 23cm-square cake tin.
2. For vanilla custard, combine sugar and cornflour in a saucepan over medium heat, add milk a little at a time, whisking until smooth. Add juice and vanilla seeds. Bring just to the boil, whisking until smooth and thick (6-8 minutes). Remove from heat, whisk in yolks, and butter and set aside.
3. Line a 23cm-square cake tin with baking paper, place a piece of pastry in base and pour over a third of the custard, level with a palette knife and top with another piece of pastry. Repeat with remaining custard and pastry. Stand for 2 hours or until set.
4. For icing, combine ingredients in a bowl and mix. Spread over slice and serve.