My version of this popular cake is based on the Vanilla slices I remember from a local bakery as a boy, Vanilla slices can be a little bit tricky to make if your vanilla custard is not tight enough, you need a good firm custard which can hold it’s shape when sliced. I use a thick pastry cream for the filling, Pastry cream is by nature is quite soft but I use extra flour and custard powder to create a good thick tight custard. In a modern day commercial bakery, these cakes would be made using a cold custard mix which has a pre-gelatinized starch, these cold custards are simply mixed with cold water, and it seems a common practice to make the custard very thick so that it has good slicing and handling properties but this does not necessarily enhance the eating quality of the custard, and I have come across examples which can seem to have a slightly dry rubber like eating quality.
On-board most ships we just don’t carry these cold custard mix’s so we must make our own custard, you could make any thick custard of your own for this recipe if you wish to experiment, but the pastry cream I have use here does have a lovely taste and an acceptable consistency suitable for these Vanilla slices. This Recipe is in 2 parts and here we will looking at the baking, construction and finishing of the Vanilla Slice and deal with making the pastry cream in a separate recipe, which we have already posted.
(See separate recipe for Pastry Cream which needs to be made the day before and chilled)
Make your pastry cream in advance the day before so it can be chilled in the fridge overnight ready for use.
Lightly grease your baking trays.
Roll out puff pastry and cut into even size rectangles approximately 12cm wide and as long as your baking tray will allow. We require 2 pieces of pastry for each bar of Vanilla slice, the bars will be cut up into individual cakes later.
Place the puff pastry onto the baking trays. and puncture one piece of the puff pastry down the middle to reduce the lift, this slice of Puff pastry will be our base for the Vanilla slices. Repeat this for each tray.
Bake the puff pasty at a suitable temperature around 180C to 200C depending on your oven, what we are trying to achieve here is fully cooked and crisp puff pastry, if we under cook the pastry it will be soft and fall after its removed from the oven, equally we don't want to overcook and burn the pastry, it can take a little bit of practice to get the baking just right and find suitable oven temperature at first you have to know your ovens. One technique I have used is to lower the oven temperature towards the end of the baking and leave the pastry in longer, this allows the pastry to dry out fully and this will then ensure your puff pastry remains crisp and maintains it's lift.
When the pastry is baked remove from the oven and allow to cool on cooling wires.
When the pastry is cool we can start to assemble our vanilla slice, I like to put a piece of clean grease proof paper on the bench when working with cooked cakes and pastries rather than working directly on the bench.
Note;- The strawberry jam is optional in this cake as most examples of a vanilla slice I see do not have jam inside, and the use of jam does make assembly a little more tricky as it stops the custard from sticking to the bottom layer of pastry, But I find the jam adds colour flavour and sweetness and enhances the overall pleasure of this lovely cake, so if you use Jam just a small amount down the middle, this will allow the custard to bond with the pastry on each side. Spread a little strawberry jam on the piece of pastry which has the holes we made with the fork.
Then pipe a suitable amount of thick pastry cream down both sides of the jam, then on top of the jam.
Now take the other piece of puff pastry and turn it up side down on top of the pastry cream and gently press it so it adheres to the pastry cream, you should now have a perfectly flat top ready to accept your water icing. Once the top is on I run the point of a sharp knife down the greaseproof paper to cut it and make it easier to move the cakes around the bench ready for icing.
Make some water icing with boiling water and Icing sugar and put a small amount in a separate bowl and add some pink or red food colour.
Water Icing is the simplest of icing and simply made by adding boiling water to Icing Sugar, the key is to only as little water as possible, so care is required when adding the water.
At this stage you will have several long bar cakes on your bench, we will ice each bar cake individually, the feathering pattern on each cake must be done before the white watering icing generates a crust, so make a greaseproof piping bag and fill it with pink icing ready to pipe soon as you have spread your white water icing. I will put some images of how to make a piping bag at the bottom of this recipe.
Take one bar cake and spoon some white icing onto the top of your cake, then spread the icing evenly over the top of your puff pastry with a pallet knife trying to ensure as much as possible it does not drip over the edge of the pastry too much.
Snipe a small hole in the pink icing bag and pipe the coloured icing along the length of the cake and then use a toothpick to make a feather pattern by dragging the toothpick in alternate direction across the cake to create the feathering effect.
To cut your vanilla slice take a sharp serrated knife and a jug of very hot water. dip the knife in the water to heat it up and have a cloth standing by on the bench. remove the knife from the jug of hot water and wipe it dry on the cloth and using a sawing action cut the top layer of puff pastry so it is cut through to the custard. repeat this along the cake dipping the knife in the hot water and wiping off the excess water in between each cut.
The finished Vanilla Slice