Preheat the oven to 200°C, fan oven 180°C, gas mark 6.
Make the topping: In a food processor, add the bread and pulse until fine crumbs form.
Transfer the breadcrumbs to a medium bowl and stir in the muscovado or light brown sugar, cinnamon and salt. Add the melted butter, stir well to combine, then set aside.
Make the filling: In a medium bowl, combine the plums, sugar, cornflour, a pinch of salt, lemon juice and vanilla extract.
Spoon the plum filling into a deep rectangular or square baking dish and cover with an even layer of the topping.
Bake until the plums are tender and look juicy around the edges of the baking dish, and the topping is golden-brown - about 20 minutes. Serve warm or at room temperature.
*All information included in this recipe has been provided by South African Stone Fruit. This recipe was created by Reuben Riffel, head chef at Reuben's Restaurant, Franschhoek, South Africa.