1For the Mousse:
2Break the chocolate into pieces and melt over low heat over a double boiler.
3Add the butter and whisk. Then remove from heat.
4Add the egg yolks one at a time, whisking well. Set aside to cool.
5Beat the egg whites while pouring the sugar.
6Fold 1/4 of the whites into the chocolate, mix, then pour the rest.
7Mix well and refrigerate for at least 2 hours.
8For the birthday charlotte:
9Butter the bottom of a springform pan or other mold with charlotte (15cm).
10Cut out a disc of parchment paper, butter and place it on the bottom of the mold (buttered side up).
11In a deep dish, mix the syrup, water, cinnamon and orange flower water.
12Set aside 5 cookies for the top of the charlotte.
13Soak the others one at a time, very quickly, in the syrup mixture.
14Arrange them against the wall of the mold, the rounded side towards the outside.
15Line the entire outside of the mold with the cookies, leaving the center empty.
16Pour the chocolate mousse in the center, then lay a layer of blueberries.
17Cover with the reserved cookies, quickly soaked in the syrup mixture.
18Place the Charlotte on a plate the size of the mold.
19Wrap plastic film and refrigerate for 3 hours.
20Unmold the charlotte, (preferably using the hinged mold) and then top with whipped cream.
21Sprinkle with cocoa powder or chocolate chips.