In a small saucepan over a bain-marie, melt 150 g chocolate (broken into pieces) with 35 g butter until smooth and creamy.
In a large mixing bowl, beat the egg yolks with 75 g powdered sugar until pale and fluffy. Sift in 50 g flour, then fold in the melted chocolate mixture, 1 tablespoon aged rum, and 1 teaspoon baking powder.
Beat the egg whites to stiff peaks and gently fold into the batter for a light texture.
Pour into a generously buttered crown mold. Bake in a preheated oven at th.6 (220°C) for 10 minutes, then reduce to th.4 (180°C) for 8 more minutes.
Remove from the oven, cool completely, and unmold onto the center of a serving dish.
For the glaze, melt the remaining 150 g chocolate with 2 tablespoons water and 30 g butter over a bain-marie. Stir in 2 tablespoons aged rum.
Pour the warm glaze over the crowns, coating evenly.
Fill the center with 200 g Chantilly cream (whip 250 g cream with 50 g icing sugar for best results).
