Preheat the oven to gas mark 5 and grease and line a 20cmx24cm tin.

Sift the flour in a large bowl and add the butter and rub into the flour to make breadcrumbs.

Remove 175g of the crumble mixture to another bowl and set aside.

Stir in the caster sugar and beaten eggs to the larger amount to make a soft sticky dough.

Press evenly into the tin using floured hands and scatter the diced apple and berries on top.

Stir the demerara sugar and nuts into the remaining crumble and spoon over the fruit pressing down gently.

Bake for about 35-45 mins on a hot baking sheet (covering loosely with foil after 20mins).

Bake until golden and remove from oven. Allow to cool for 20mins and serve.