Preheat the oven 280°C

Lightly butter 1.2 L ovenproof dish

Place the apples in a pan with 2 tablespoons of the butter 2 tablespoons of the sugar and 1 tablespoon waterAnd bring to the boil, then reduce the heat, cover and gently for about 10 minutes, until just tender but still holding their shape

Remove from the heat and gently stir in the blackberries.

Spoon the mixture into the oven proof dish and set aside while you make the topping

To make the crumble topping, sift the flour and cinnamon into a bowl (use any of the bran that is left in the sieve). Add the remaining 6 tablespoons of butter and rub into the flour with your fingertips until the mixture resembles fine breadcrumbs - you can use a food processor

Stir in the remaining 6 tablespoons sugar and the nuts and mix well

Sprinkle the crumble topping over the fruit and bake for 35 to 40 minutes until the top is golden brown

Serve hot with custard, cream or ice cream