This wonderfully warming, autumnal crumble is very adaptable: I love the combination of plum and blackberries with the spices and hazelnuts, but you can use plums alone, or swap them for blackberry and apple, or just apples.
And it has one big advantage: you make the filling and topping a day or more ahead and bring them together just before you want to eat, giving you more time to spend with family and friends. And we all need a bit of that after the past 18 months.
The overnight steep is essential to allow the spice flavours to infuse into the filling. If you want instant results, use half a teaspoon of ground cinnamon instead of the whole spices and maybe a pinch of ground cloves, omitting the star anise. That would be a shame, though, as it marries so well with the fruit.
The weight given in the recipe is for pitted plums. When I prepared mine, 1kg of plums gave me 800g stoned weight, so reckon on losing about 20%, depending on how hard your plums are to pit. Of course, you can keep the stones in, but this is one dish where I don’t want to be playing tinker, tailor, soldier, sailor.
I used skinned, ready toasted hazelnuts. To toast them from scratch, check out this BBC video with Sophie Grigson. Another way to get any skins off is to wrap them, while still warm from the oven, in an old, clean tea towel. Once they’ve cooled, rub them in the cloth to remove the skins.
I cooked my crumble in a round, ovenproof earthenware dish which is 22cm in diameter and 5cm deep. You can make individual portions instead, but again, don’t add the topping until just before you cook them. If you’d like to freeze them, put the topping in a bag and freeze it separately.
Spiced Plum and Blackberry Crumble
Ingredients for the filling:
Around 800g-1kg dark, pitted plums and blackberries in about a 2:1 ratio
3 heaped tbsp soft light brown sugar (plus more, to taste)
1/2 cinnamon stick
2 star anise
For the topping:
100g plain (all purpose) flour
100g Demerara sugar
3/4 tsp ground cinnamon
1 heaped tbsp porridge oats
50g chopped toasted hazelnuts (I like mine rubbly and nubbly but go for the texture you like)
Put the stoned plums and blackberries in a bowl, stir in the soft light brown sugar, cover and if you have time, leave to macerate.
Make the crumble topping: put the flour, butter, ground cinnamon and sugar in a food processor and whizz until the mixture looks like breadcrumbs (don’t overdo it, some clumping is fine, but you don’t want boulders). Alternatively, rub it in between the fingertips. Tip into a bowl, stir through the oats and nuts, cover and set aside in the fridge.
Put the macerated fruit (or if you didn’t have time, simply the fruit and sugar and a tiny splash of water) in a saucepan and add the whole spices. Cook on a low heat until the juices run and you can smell the spice aroma – about 10 minutes. Don’t let the fruit break up.
Check the sweetness and add more sugar if necessary – I like mine quite tart. Then scoop into a bowl, keeping the spices in the mixture. Cover, cool and refrigerate overnight. You can leave it up to two days if that suits your timings better.
Shortly before you want to eat, heat the oven to 180C/160 fan/350F/Gas Mark 4. Remove the spices from the bowl and discard them. Using a slotted spoon, scoop the fruit into a heat-proof oven dish.
You may find it’s produced too much liquid. In north America it’s usual to thicken the juices in fruit pies and crumbles/crisps with cornflour (cornstarch) but I prefer mine unadulterated and keep any extra to pour over ice cream or my breakfast porridge another day – the choice is yours.
Sprinkle the crumble mixture over the fruit and cook for 25-30 minutes until golden brown and bubbling. Allow to cool for 10 minutes before serving with cream, ice cream or crème fraîche. Oh, alright, or custard.