My dad's favourite cake: a classic soft yeast dough topped with fresh plums, cinnamon sugar and sliced almonds.
Mix the flour, sugar, vanilla sugar, cinnamon and crumbled yeast together in a mixing bowl.
Add the lukewarm milk, salt and soft butter and knead for about 5 minutes into a smooth yeast dough. Cover and leave to rest for 60 minutes.
Heat the oven to 180°C top and bottom heat (160°C fan) and grease a deep baking tray, about 38 × 45 cm.
Put the dough into the tray and press it flat and even.
Press the plum halves into the dough at a slight angle, then scatter the sliced almonds and cinnamon sugar over the top.
Bake in the preheated oven for about 55 minutes. If the almonds start to get too dark, cover the cake with aluminium foil.
Let cool before cutting.
Traditionally this is made with German Zwetschgen (prune plums), which are firmer and hold their shape in the oven; any ripe, firm plums will work.