Biscuit topped apple crumble

We got a bag of apples off an uncle last week so I decided to make a crumble. I had a packet of hazelnuts in the fridge, with some rough instructions on how to make a rhubarb crumble, so I adapted them.

150g of oat biscuits (I used a mix of hobnobs and digestives)
50g of whole hazel nuts
700g of cooking apples
2 tbsp of sugar
A couple of tbsp of water

Preheat your oven to 200 degrees c.

First toast the hazel nuts under a hot grill. This only takes a few minutes. Keep an eye on them as they burn easily. When they are done, allow them to cool and chop them roughly.
Next chop up the biscuits and give them a good bashing. No point in getting too fussy about this, nice and rough is just fine.
Peel and slice the apples and put them in a pan with the water and sugar. Bring to the boil and simmer gently for about 5 minutes. Pour the lot into a casserole or deep pie dish. Mix the biscuits and nuts together and spread them over the apple mixture. Put it in the oven for about 15 minutes. Serve with some vanilla ice cream.