Hi W - No quantities cos you can judge the feel of the mix easily enough. You want toget a dry crumb...
flour, butter (must be cold diced, not warm and sticky to start with), brown sugar, add oatmeal as well for crunch effect. Season with cinnamon and nutmeg. Slice apples, Place in baking dish. Top with crumble mix. Bake 30 mins.
Eat warm with creme fraiche, double cream, frozen yoghurt, custard, creme anglaise, whatever. Do not share......
Adding anything else? Use cranberries, use raspberries, use plums, use apricots, use rhubarb, use gooseberries, etc etc Raisins? I don't think so.....best thing to do with them is soak in sherry, dip in melted chocolate and leave to cool, then eat them all in one go....