Preheat the oven to 375°F (190°C) and position the rack in the center.
Butter an 8-inch (20cm) springform pan and line the bottom with parchment paper. Butter the parchment paper and set aside.

For the cake:
Combine the ground pecans, flour, and salt. Set aside.

In a saucepan, combine the prunes and 1/4 cup (60ml) of water. Bring to a boil and cook until the liquid has almost completely evaporated.
Add the Armagnac and cook for a few seconds before igniting the mixture. Let it burn for a few seconds and then extinguish the flames. Let cool to room temperature.

In a double boiler, combine the chocolate, butter, and remaining 3 tablespoons of water. Heat, stirring occasionally, until the mixture is smooth. Set aside.

In a mixing bowl, beat the egg yolks and sugar for 2 minutes.
Add the melted chocolate, prunes with their juice, and the flour mixture. Beat until well combined.
Fold in the egg whites, beaten until stiff peaks form.

Pour the batter into the prepared pan and bake for 28-32 minutes.

Let the cake cool in the pan before pouring the glaze over it.

For the glaze:
Combine all the ingredients in a double boiler and heat, stirring occasionally, until smooth. Let cool before spreading over the cake.