Preheat the oven to 175 C / 350 F. Grease the loaf pan and dust it with flour.
Separate the eggs.
Beat the softened butter with the 200 g sugar until light and frothy. Now, using the hand mixer on low speed, a spatula or a big handheld whisk, gradually fold in the egg yolks, then fold in rum, vanilla, ground almonds and poppy seeds.
Beat the egg whites with salt until stiff. Fold the egg whites very gently into the batter.
Pour the dough into the greased loaf pan and bake in the preheated oven at for about 55 minutes. Let cool in the pan for 15 minutes before turning over.
Let cool in the pan for 15 minutes before turning over.
Drizzle the cake with a simple icing made with powdered sugar and lemon juice or drizzle it with melted white chocolate.