Preheat the oven to 180°C (approximately 350°F) convection. Chop the dark chocolate and ginger. Melt the butter with the chocolate in a bowl over a hot water bath, set aside and let cool slightly. Separate the eggs. Beat the egg whites with a pinch of salt until stiff. Beat the egg yolks and sugar until light and creamy. Stir the chocolate mixture into the egg yolk mixture. Mix in the ginger, almonds and raisins.
Sift together the flour, baking powder and the cocoa and mix with the chocolate mixture. Fold in the egg whites and the rum. Pour the batter into a greased loaf pan and smooth with a spatula. Bake in the preheated oven about 45 minutes until a toothpick comes out clean. Cool in the pan slightly, then remove from the pan and let cool completely on a wire rack. Cut into slices and serve.