Cut apples into bitesize chunks, about 1inch cubes. Put cubed apples, sugar and cassis (if using) in a saucepan and cook on low for 15 minutes.
Pour apples into the ceramic dish.
Make the crumble topping by whizzing butter and flour together in a food processor, or rub butter in with your fingertips, until it resembles a sandy texture.
Mix brown sugar and chopped nuts (if using) into butter and flour mixture. Spread it over the stewed apple.
Bake for 30 minutes or until golden! Serve hot with either double cream, custard or vanilla ice cream!!
Notes
When stewing apples, you don't want the apples to be totally mushy as they carry on cooking in the oven.