Preheat the oven to 180ºC (350ºF) fan-forced. Grease a 25cm (10-inch) round pie dish with butter and set aside.
Chop apples: Chop the apples into small cubes/chunks, approx. 1/2-inch in size. Discard the core and place apples in a mixing bowl.
Add Ingredients: To the apples,add the blueberries, sugar, lemon juice, cinnamon, vanilla, and salt. Mix until well combined.
Add Flour: Sprinkle over the flour and mix through until the fruit is coated in the flour.
Transfer Filling: Spoon the filling into greased pie dish.
Crumble Topping
Combine Dry Ingredients: In a medium size mixing bowl, add the flour, oats, sugar, and cinnamon. Mix to combine.
Add Butter: Pour in the melted butter and mix until a crumbly dough forms.
Add To Filling: Sprinkle the crumble over the filling.
Bake: Bake for 40-45 minutes until golden and bubbling. Remove from the oven and allow to cool slightly.
Serve: Serve warm with ice cream or cool and reheat later. Enjoy!
Notes
Store: Once the crumble has cooled, either leave it in its pie dish or transfer it to an airtight container. When stored in its pie dish, cover with plastic wrap or foil. Refrigerate for 2-3 days.Freezer: Transfer the cooled crumble to a freezer-safe, airtight container. Label with the date and store in the freezer for up to 3 months.Thawing & Reheating: Thaw frozen crumble overnight in the fridge or at room temperature for several hours. Reheat in a preheated oven at 350°F (175°C) for 15-20 minutes, or microwave on medium for 2-3 minutes, or in an air fryer at 400ºF (200ºC) for 5-8 minutes.