Quarter the apples, remove the core, and slice. Place in a pan with the spices, sultanas if using and water, and bring to a gentle simmer for 10 minutes. Remove from the heat and transfer to an ovenproof dish. approx 10 x 8 inches. If you are using cooking apples, there's no need to simmer them first as they'll soften in the oven whilst cooking the crumble. Simple place the sliced raw cooking apples into the baking dish.
Preheat the oven to 180 degrees (160 fan) Place the oats, ground almonds, sugar and butter in a food processor. Pulse very gently until mixed. Sprinkle the topping over the fruit mixture and bake for 30 minutes until golden.
Notes
If your apples are very sharp, you might want to add a spoonful of sugar or honey to the apple mix.