FOR THE PUFF PASTRY

1 Preheat the oven to 200 degrees (180 fan). Line a 20cm x 20cm square baking tin with two sheets of parchment paper, leaving 5cm of paper hanging over the edges. This will make it easier to remove from the tin later.

2 Cut four pieces of parchment paper to fit four baking trays and line two of the trays. If you don’t have four trays, bake the pastry in two batches. Divide the puff pastry into two and dust the work surface with a little icing sugar. Roll one pastry piece into a large square, dusting with icing sugar as you go, until you have a square about 22cm x 22cm. Place the pastry square on the prepared tray and place another piece of parchment on top, followed by another tray. Repeat with the other piece of pastry. Bake the pastry for 20-25 minutes until golden and crisp.

3 Remove the pastry from the oven and trim the pastry into two 20cm x 20cm squares to fit the square baking tin. Set aside.

FOR THE VANILLA CUSTARD

1 Place the gelatine leaves in a bowl and cover with cold water.

2 Put the cream and milk into a large saucepan with the vanilla and gently bring to a simmer. In a bowl, whisk the egg yolks, sugar and cornflour together until pale.

3 Once simmering, pour the hot cream over the egg mix, whisking all the time, then pour back to the saucepan and place on a low heat.

4 Cook the custard, whisking all the time, until it starts to boil, then remove from the heat. Squeeze the water from the gelatine leaves and add them into the custard, whisking well to dissolve. Allow to cool slightly.

TO ASSEMBLE

Place one pastry square in the baking tin and spread the custard on top. Place the second pastry square on the custard and chill completely for at least four hours before cutting into slices and dusting with icing sugar to serve.