Pre-heat the oven to 180°C if not using air fryer.
Put 30 g unsalted butter, caster sugar and Muscovado sugar in a large non-stick pan over a low to medium heat to make a caramel base.
Once butter has melted add 1 tablespoon water and stir with a wooden spoon until sugars have dissolved.
Peel, quarter and core pears (and apples if using) adding them to the pan as you prepare them, turning in the caramel to prevent browning. (This way you don't need to use lemon juice to prevent browning).
Allow the pears to soften on a gentle heat and go slightly golden, turning from time to time.
Meanwhile prepare crumble topping. Put 75 wholemeal spelt flour and 50g of butter in a food processor or rub together with fingertips to form texture of breadcrumbs
Stir in Demerara sugar, oats, chopped almonds, dark chocolate and crystallised ginger.
Add 1 tbsp water and shake to form small lumps.
Remove caramelised pears from heat and pour into a 1.5 litre (20 cm round) oven proof dish.
Then pour over the crumble topping, spreading evenly with a fork, don’t pack it down.
Pre-heat air fryer for 4 minutes at 180°C and then bake for 13 minutes or until crisp and golden. For oven method, place on middle shelf and bake for 40 – 45 minutes.
Serve hot with ice cream, cream or custard. Can also be eaten cold.