Based on an old French recipe notebook dated back to 1895
1 package of boudoir biscuits (or homemade boudoir biscuits from the same notebook)
For the Bavarian cream:
1 liter of milk
250 g sugar
10 egg yolks
5 sheets of gelatin
1 liter of milk cream (30 % fat)
1 dose of vanilla
Whisk the egg yolks and sugar until they double in volume. Then pour in the milk and vanilla. Transfer the mixture into a saucepan and bring to a boil in a water bath. Stir constantly until the cream begins to coat the spoon.
Soak the gelatine in cold water, then drain and put into the hot egg cream. Stir to melt. Let it cool to about 20°C. In another bowl, whisk the milk cream until stiff peaks and stir it into the egg cream.
Line a cake pan (26-28 cm) with boudoir biscuits (bottom and sides). Pour over the cooled bavarian cream and refrigerate for several hours or 1 day. Unmold before serving.
The recipe does not specify the existence of a decoration or fruit in the charlotte. It just gives a choice between vanilla or coffee flavored cream. I had some homemade caramel (made of 3 tablespoons sugar and 1 teaspoon butter) and just decorated the cake with a handful of caramel chips.