Preheat the oven to 180°C/gas mark 4. Put the apples, orange juice and zest and 60g sugar in a pan and simmer gently for 15 minutes, until the apples begin to soften. Transfer the cooked apples to an ovenproof dish.
Put the remaining sugar, the flour, oats, butter and cinnamon in a food processor and pulse until the mixture resembles coarse breadcrumbs. Scatter the crumble mixture over the fruit and bake for 30-40 minutes, until golden. Serve warm.