Put the plums in an oven-proof dish. In a bowl, add the sugar, cinnamon and corn flour and mix together. Sprinkle on top of the plums.
For the topping, put the flour in a bowl and rub in the butter until like fine breadcrumbs. Stir in the sugar. Sprinkle the topping evenly over the plums and bake for 35-40 minutes until golden. Serve the crumble hot.
Get your ingredients deliveredCheck out Ocado! Save 25% on your first order + 3 months free unlimited deliveries. Enter VOU7389477 at checkout