Base: mix all ingredients to a dough. Roll out two thirds of the dough on a bit of flour with a rolling pin. Butter the tray and put the flat dough inside, then leave it in the frifge for 30min.
Topping: Wash the plums, cut on the long side while keeping the halves connected, and remove the cores. Preheat the oven to 180 degrees (fan forced).
Crumble: Mix the flour, nuts, butter, sugar and cinnamon in a bowl until crumbs form.
Place the plums into the tray in a circular pattern, with the inside facing up. Spread the crumble on top and place into the preheated oven. Bake for 45-50 min at 180 degrees.
Calories per slice (12 slices per cake)- 350 Calories per slice