Preheat the oven to 180°C bake or 160°C fan bake. Lightly grease a medium-sized baking dish.
Pour the canned apples and pears, along with all the juice, into the prepared baking dish. Sprinkle over the cinnamon and nutmeg and gently mix together.
In a large bowl, combine the flour, brown sugar, baking powder, and salt.
Add the softened butter and rub it into the dry ingredients using your fingertips until the mixture resembles chunky breadcrumbs. A few larger buttery pieces are perfectly fine and help give the crumble a good texture once baked.
Sprinkle the crumble mixture evenly over the fruit filling without pressing it down.
Bake for 20–30 minutes, or until the crumble is golden on top and the fruit is bubbling around the edges.
Let the crumble rest for about 10 minutes before serving.
Serve warm with custard, cream, or vanilla ice cream.