Vanilla Custard Slice

 

Vanilla Custard Slice - captured!

INGREDIENTS

Base

• 2 sheets of frozen puff pastry
  

Filling

• 1 cup + 2 tbsp (250g) caster sugar
• 1/3 cup + ¼ cup (90g) corn flour
• 1/3 cup (50g) custard powder
• 3 cups (750ml) milk
• 1 cup (250ml) cream
• 60g butter
• 3 tsp vanilla essence
  
• 3 egg yolks

Topping

• 1 ½ cups (225g) pure icing sugar, sifted
• 2 tbsp (40ml) milk
• 1 tsp vanilla essence

 METHOD

1. Preheat oven to 180 C and defrost puff pastry sheets. Line two baking trays with baking paper and lay the pastry sheets on top, then place another baking tray on top to prevent the pastry rising too much during baking. Bake for approximately 20 minutes, or until the pastry is golden. Remove from oven and allow to cool completely.
2. Line a 23cm square tin with aluminium foil, extending it over the sides so you can use it as handles to remove the slice when cool. Place one sheet of pastry in the base of the tin, top (golden) side down.
3. Combine the sugar, corn flour and custard powder in a saucepan, then gradually add half the milk and whisk until smooth. Add the rest of the milk, and cream and stir over medium heat until mixture boils and thickens. Reduce heat to low, add butter and vanilla essence and whisk until the butter is melted and the mixture is smooth. Remove the pan from heat, then whisk in the egg yolks until combined.
4. Spread the vanilla custard over the pastry in the tin, then place the second sheet of pastry on top (top/golden side down) and allow to cool.
5. Combine the icing sugar, vanilla essence and milk, mix until smooth, then spread over the top of the pastry. Set the entire slice in the refrigerator for about six hours before slicing and serving. Use a long serrated knife to cut (e.g. a bread knife).
   

NOTES - 19 September 2020 

This is the definitive recipe. 

Like most custard recipes, this one placed a lot of emphasis on boiling the mixture for at least a minute to ensure it set properly. With my previous experience with very firm custard, I wasn't so concerned about this, and so I really just looked out for the first sign that the mixture was thickening up to a custard, and then reduced the heat for the next bit of the process.

On this occasion it worked very well - the custard did hit the sweet spot range between too soft to cut and too firm to enjoy, though it could have stood to be a little firmer, because the custard was in danger of being squeezed out in the slicing process. 

The use of proper pastry was a definite improvement, and backing the icing off to a sane volume and colour helped to establish a good basic example of the slice.

Pay close attention to the dimensions of your frozen puff pastry and your slice pan - if you don't have an exact match, you're going to end up having to trim the pastry and possibly grafting a bit on the end, to fill the pan. This is never going to be as effective as using a piece of fresh pastry cut to fit the pan perfectly. If the pastry is smaller than the pan, and your custard is on the runnier side, you'll also end up with it running over the edge of the pastry onto the tin base, and bulging out the sides of the slice. None of these things are ideal, but unfortunately making things ideal will probably require acquiring a slice tin of the exact dimensions of your off-the-shelf pastry, or working a bit more with the pastry than this recipe suggests is necessary. I may be willing to make those sacrifices on your behalf, in future.

With the icing, I know there is a strong following for passionfruit pulp to be part of the topping of this slice. Some people like it, some don't - I don't. But if you're going to add it, it's as simple as combining the pulp of as many passionfruits as you wish in the icing mixture prior to spreading. I would think two would be sufficient, three may be over the top. Be aware that very small amounts of moisture affect the consistency of icing, so probably add the pulp before the milk, and I would back the vanilla essence off to one teaspoon, or possibly none. Similarly, coloured icing has its following, and it's easy enough to colour icing if you wish. I like my vanilla custard slice to be nice and vanilla.

Storage is a challenge with this one. If you keep it in the fridge, the pastry will go soggy and curl within a couple of days, which is unpleasant. The presence of real egg in the custard, which is only really cooked by the residual heat in the nearly-finished mixture, means an unrefrigerated shelf-life should also be limited. So my best suggestion here is to make this slice specifically to be consumed within the first two days, e.g. for a special occasion rather than to create a stock of snacks in the house.