Remove the crust of the brioche bread, cut into 1/3 inch thick slices and brown in the oven on both sides. Beat the eggs, the sugar and the vanilla sugar together, gradually add the scalding milk, whisking constantly. Generously butter a pie pan, spread one layer of bread, cover with a thin layer of chopped candied fruit (soaked in the rum), then add another layer of bread. Build up the layers to the top of the pan, ending with a layer of bread. Put about 2 laddles of milk and egg mixture, through a strainer, over the pudding. Let the bread soak up the liquid, add 2 more laddles, leaving it to soak up again and continue the process until the milk is visible around the bread. Bake in a bain-marie, in a medium oven (250-300F). Halfway through, add the remaining egg and milk mixture. Take out of the oven and leave to cool.
For the meringue: wet the sugar and cook to the soft ball stage (a bit of sugar dropped onto a humid plate is still supple when cool). Whip the egg whites firm, and add the liquid sugar in a stream, whisking constantly until cool. Frost the pudding with meringue, first using a spatula then decorating with a pastry bag and star tip. Sprinkle with confectioners╒ sugar and bake in a very low oven until the meringue has hardened without coloring (25 minutes).
