Step 1: Prepare the Fruit Filling
Preheat your oven to 180°C (350°F). In a mixing bowl, combine the chopped apples, blackberries, sugar, lemon juice, and cinnamon. Stir gently to mix, then transfer the fruit mixture to a baking dish, spreading it out evenly.
Step 2: Make the Crumble Topping
In a separate bowl, combine the flour and butter. Rub the butter into the flour using your fingertips until the mixture resembles coarse breadcrumbs. Stir in the sugar and oats (if using) to create the crumble topping.
Step 3: Assemble the Crumble
Sprinkle the crumble topping evenly over the fruit mixture in the baking dish, making sure the fruit is completely covered.
Step 4: Bake
Place the baking dish in the preheated oven and bake for 35-40 minutes, or until the topping is golden and the fruit is bubbling around the edges.
Step 5: Serve
Allow the crumble to cool slightly before serving. Serve warm with custard, cream, or a scoop of vanilla ice cream for a truly indulgent dessert.
