Method
1. Pre-heat oven to 180°C. Peel, and core the apples. Mix them with the sugar and sultanas then cover with lemon juice.
2. Line your baking dish (approximate size 20cm x 15cm and about 5cm deep) with the apple mix and set aside while you make the crumble mixture.
3. In a food mixer, combine the flour, sugar and salt. Add 200g of the softened butter and work into the mixture until it is well combined and looks like slightly moistened, coarse breadcrumbs. Now chop the remaining 50g of softened butter and add to the mixture. Pulse until the mixture takes on a more crumbled texture.
4. Cover the apples with this mixture. Bake in the oven for about 45 minutes until the apples are cooked (you will see the juices bubbling at the sides) and the crumble topping is golden.