Preheat the oven to 190°C/Fan 170°C/Gas 5 and put a baking tray on the middle shelf to heat. Chop the dried fruits into bite-sized pieces and place in a non-reactive saucepan.
Add the wine, mulling spices, orange zest and caster sugar. Heat gently, then let simmer for about 10 minutes. Set aside to cool.
Spoon the semi-cooked dried fruit into a baking dish and remove the mulling spices and orange zest.
To make the topping, put the flour, mixed spice, salt and butter into a food processor and process until it looks like coarse breadcrumbs. (Alternatively you can rub in by hand.) Tip the mixture into a bowl and stir in the sugar.
Lightly sprinkle the topping mixture evenly over the surface of the dried fruits, mounding it up a little towards the centre.
Place on the hot baking tray and bake in the preheated oven for about 25 minutes, until crisp and golden on top. Remove from the oven and let cool for 5 minutes before serving with clotted cream.