Vínarterta (Icelandic prune layer cake)

Instructions

1. Soak the prunes in water for 1 hour, then cook them for 15 minutes over low heat with the sugar and cinnamon until you have a thick jam.
2. Blend the prune jam until smooth, then let it cool completely.
3. Beat the butter and sugar until pale and creamy, then add the eggs one at a time.
4. Mix in the vanilla and cardamom, then the sifted flour with the baking powder and salt, adding the milk to make a soft dough.
5. Divide the dough into 4 or 5 portions and roll each into a disc about 20 cm wide on a baking sheet.
6. Bake each disc for 8 to 10 minutes at 190 °C, until golden at the edges and firm to the touch.
7. Stack the cooled discs, spreading a layer of jam between each, then let it rest for 24 hours so the layers soften.