Preheat oven to 200º C.
Put all filling ingredients in a big pan to stew slowly with a little water until soft.
Spoon apple mixture into a wide ovenproof dish.
Put all topping ingredients into a bowl and rub in. Alternatively dump it into a food mixer and run slowly until well combined.
Scatter the topping over and bake for around 25 minutes until golden on top.
I served mine with double cream mixed with vanilla bean paste to make a vanilla cream. Custard, and vanilla ice cream also work well.