This is a wonderful combination of crunchy, nutty crumble with a deep filled slice of apple tart. If you have a long tin, this cooks nice and evenly then slices neatly for presentation – which is often difficult for either a crumble or a tart! Try adding some blackberries if you have picked some. This also freezes really well.
Tip: Be careful not to over process or melt the butter too much as the topping will become a heavy mass. It’s better to store the topping in the fridge until needed.