Principle
A charlotte mould is lined in the bottom and around the sides with syrup-soaked biscuits. This outside layer is then filled with a cream and left to set in the fridge (usually overnight).
Mould
Of course, it is best to use a proper charlotte mould if possible. This is round and tall with tapering sides which make turning out easier. If the mould is non-stick, so much the better, as there is no need to butter it.
If you are worried that the charlotte will not turn out properly (it might stick on the bottom and fall apart) you can put a circle of paper or plastic film in the bottom of the mould.
Biscuits
Boudoir or sponge finger biscuits are the ones most commonly used – they are just right for this. If you don't have any, you can use slices of genoa sponge or brioche.
Soaking syrup
The biscuits are soaked in the syrup until they have absorbed some of it up before being arranged around the sides of the mould. The syrup needs to be well-flavoured and quite runny so that the biscuits can soak it up easily (a fruit coulis, for example, is thicker, so would need a longer soaking time).
Please note that there is a delicate balance to be struck between biscuits that are too dry or too soggy. Personally, when using a very liquid syrup (such as coffee), I soak the biscuit in the syrup, then take it out and remove the excess by pressing.
It is traditional to line the mould with biscuits arranged vertically around the side, then arrange more biscuits in the bottom. Of course, the biscuits won't be the right shape and will need to be cut to fit to give an even layer.
Cream filling
Once the outer "casing" is in place, this is filled with a cream that should set when cold. This is typically made with gelatin or agar-agar. One of the best results comes from using (about 50/50) whipped cream with something else that contains dissolved gelatine. This other ingredient can be a fruit coulis (fruit purée), custard (crème anglaise), creamy cheese like mascarpone, etc.
You can also make the charlotte in different layers: cream, diced fruit, cream. However you fill it, do be sure to fill the mould full, even round the top a little, as the cream will tend to sink a little as it sets.
You can also finish with a layer of biscuits, so that the charlotte has a complete outer shell. This is simply for appearance and a matter of taste.
Once the cream has been poured into the mould, cover with plastic film and leave to set in the fridge overnight.
Shortly before serving, turn out carefully and slice vertically. Serve the slices laid flat for best effect, surrounded by a coulis, sauce or custard if you wish.
Charlotte?
The dessert's origins are uncertain. The name might refer to the British queen Charlotte who was the wife of George III.
