6. Once the pastry is completely cooled carefully slide the pastry onto a chopping board and use a serrated bread knife to divide it into two equal pieces, these will form the top and base of the slice. Place one piece onto a baking tray or flat plate and prepare the creme patissiere. Rather than pouring it into a plastic container as instructed in the recipe, pour it directly over the pastry and spread it as evenly as you can with a crank handle palette knife or dessert spoon. This will form the base of the slice. It’s vital that you follow the creme patissiere recipe exactly to ensure that it is thick enough to spread over the pastry without running off the edges.
7. Refrigerate the base until the creme patissiere is set and completely cooled. If there is any warmth at all in the custard before you move to the next step you will end up with a melted puddle of whipped cream.
8. Add the cream, rum, sugar, vanilla and skim milk powder to the bowl of a stand mixer and whisk to stiff peaks. Spread the cream evenly over the surface of the creme patissiere and place the remaining piece of puff pastry, shiny side up, over the surface. Gently press down over the top of the slice with your hands to ensure that the cream makes contact with the pastry over its entire surface. Return the slice to the fridge for 30 minutes to set the cream. The skim milk powder will stabilise the cream, helping it to stay whipped and firm for much longer than it would without it. However it does need the 30 minutes of resting time to properly set so that you don’t end up with a squishy mess when you’re trying to cut the slice.
9. Using a serrated knife and wiping after each slice, carefully trim all four edges off the slice so that you can see the beautiful layers of cream and custard and the golden flakes of the pastry. Use the serrated knife to cut the slice into 8 equal pieces (or as many or few as you like), and dust the tops generously with icing sugar to serve. Place a strip of baking paper or another stencil over the slice before dusting then remove it afterwards to make the best use of your beautiful shiny pastry.
This slice is tastiest and the pastry is most crisp on the day of baking, but it is still good to eat up to 2 days later if stored in a sealed container in the fridge.
Crème Pâtissière
Ingredients
3 medium egg yolks
60g caster sugar
2 tbsp cornflour
25g unsalted butter
250g full cream milk
½ tsp vanilla paste
Method
1. Place the yolks in a medium size bowl and set the whisk inside it, the sugar, cornflour and butter each in separate small bowls. You will make a far better custard if you weigh everything beforehand. Creme patissiere is always best when made quickly, and being unprepared is likely to result in a burnt or curdled mess.
2. Add the milk to a small saucepan with the vanilla and bring to the boil over a medium heat, whisking occasionally. As the milk starts to simmer and gets close to boiling quickly whisk the sugar into the yolks, followed by the cornflour. Adding the sugar to the yolks too soon will “burn” the yolks and the creme patissiere will be grainy. Whisking in the sugar and cornflour separately reduces the chance of lumps.
3. When the milk is at a rolling boil quickly remove it from the heat and pour approximately one third of the milk into the yolks. Whisk to combine completely and then pour it back into the saucepan.
4. Return the saucepan to a medium heat and whisk until it comes to the boil again. Whisk like mad as the custard boils for two minutes then remove from the heat. The creme patissiere will thicken so it can be tricky to saucepan the boil, keep an eye out for big bubbles that splutter.
5. Remove the saucepan from the heat and whisk in the butter, continue whisking for two minutes. The extra whisking will make the creme patissiere beautifully smooth and spreadable rather than setting like a jelly.
6. Pour the creme patissiere over the pastry base and spread as evenly as you can with the back of a spoon. Press cling wrap over the surface to stop a skin forming as it cools.
