Classic Vanilla Millefeuille with Crème Pâtissière

On a lightly floured surface, roll the cold puff pastry into a rectangle approximately 40cm × 30cm and 3mm thick. Transfer to a large baking sheet lined with parchment. Prick the surface all over with a fork, leaving no spot more than 2cm apart. Lay another sheet of parchment on top and place a second heavy baking tray directly on top to press the pastry flat during baking.

Refrigerate the prepared pastry, weighted and uncovered, for 30 minutes.

Preheat the oven to 200°C, or 180°C for a fan oven, or gas mark 6. Bake the weighted pastry for 20 minutes until the edges are beginning to colour and the pastry is set and pale golden beneath the top tray.

Remove the top tray and parchment, dust the pastry surface evenly with sifted icing sugar, and return to the oven for a further 10–12 minutes until the sugar has caramelised to a deep, even amber lacquer — watch closely as it can burn quickly.

Slide the pastry onto a wire rack and leave to cool completely to room temperature. Trim the edges with a sharp serrated knife and cut into three equal rectangles of identical size (approximately 12cm × 30cm).

For the crème pâtissière: combine the milk, vanilla pods and scraped seeds in a medium saucepan over medium heat. Bring just to a simmer — small bubbles will appear at the edges — then remove from the heat and leave to infuse for 10 minutes.

In a large bowl, whisk the egg yolks and caster sugar together vigorously until pale and thick, then whisk in the cornflour until fully incorporated with no lumps remaining.

Remove the vanilla pods from the warm milk and bring the milk back to a bare simmer over medium heat. Pour one-third of the hot milk into the yolk mixture while whisking constantly to temper, then pour the tempered mixture back into the saucepan.

Cook over medium heat, whisking constantly, until the custard thickens, comes to a full boil, and holds the boil for 90 seconds — this fully cooks out the cornflour and gives a stable set.

Remove from the heat and whisk in the cold butter cubes until fully emulsified and glossy. Pour into a clean shallow tray, press cling film directly onto the surface to prevent a skin, and refrigerate until completely cold and set, at least 2 hours.

Once cold, beat the crème pâtissière with a spatula until smooth. In a separate chilled bowl, whip the double cream to soft peaks and fold it gently into the crème pâtissière in two additions until light but still holding its shape. Transfer to a piping bag fitted with a 1.5cm plain round nozzle.

For the fondant icing: gently warm the fondant with the warm water, stirring, until it reaches a pourable but thick ribbon consistency — it should coat the back of a spoon. Keep it at this consistency over the lowest possible heat. Transfer the melted dark chocolate to a small piping bag or paper cornet.

Lay one pastry rectangle caramelised-side up on your work surface. Pipe generous, even mounds of crème pâtissière in tightly packed rows across the entire surface. Set a second pastry layer on top, pressing down very gently to level. Pipe a second layer of crème pâtissière in the same manner.

Working quickly before the fondant sets, pour the white fondant over the top pastry rectangle and spread immediately with a palette knife to coat the surface in an even, smooth layer. Pipe parallel lines of dark chocolate along the length of the fondant at 1cm intervals, then drag a cocktail stick or skewer across the lines at 2cm intervals, alternating direction, to create the classic feathered pattern.

Before the fondant sets completely, lift the iced top layer and place it carefully, fondant-side up, onto the cream-topped second layer. Refrigerate for at least 1 hour to firm up before slicing with a sharp serrated knife using a gentle sawing motion.