Healthier Chocolate and Fruit Crumble - Slow Cooker

1. Lightly oil an ovenproof dish that will sit comfortably in the slow cooker cooking dish. Place an upturned saucer into the dish and pour around 2.5cm (1") of cold water. Turn the slow cooker to high. 2. For the crumble, sift the flour into a large bowl. Cut the butter into small cubes and add to the flour. Rub the butter into the flour until the mixture resembles fine breadcrumbs. 3. Stir the sugar, porridge oats and chopped hazelnuts into this mixture and set aside. 4. For the filling, peel the apples, and core and slice them thickly. Place in a large saucepan with the lemon juice and 3 tablespoons of water. Add the sultanas, raisins and extra sugar. 5. Bring to the boil slowly, cover and simmer over a gentle heat for 8 to 10 minutes, stirring occasionally and until the apples are slightly softened. Remove the saucepan from the heat and leave to cool slightly before stirring in the pears, ground cinnamon and chopped chocolate. 6. Scoop into the prepared dish. Sprinkle the crumble evenly over the top and place in the cooking dish. Cover with a sheet of lightly oiled tin foil. Pour around sufficient boiling water so it comes halfway up the side of the dish. 7. Cover with a lid and cook in the slow cooker for 4 to 5 hours until the top is golden. If you want a crispier top, remove the foil for the last 30 minutes of cooking time. Carefully remove from the cooker, sprinkle with extra caster sugar and serve immediately.