- Preheat the oven to 200C.
2. In a large bowl, add the blackberries, apples, sugar, lemon juice, orange juice, cinnamon, and 1 tablespoon of flour.
3. In another large bowl, add the granola, 1/4 cup of butter, 1 tablespoon of flour and mix together to form the topping.
4. Dot around the diced 1 tablespoon of butter in the bottom of a 26 cm cast iron skillet.
5. Add in the fruit filling. Then add the crumble topping on top of the fruit filling.
6. Cover the pan with foil and bake in the oven for about 1 hour, until the juices start bubbling through the crumble topping.