Preheat the oven to 180C, fan 160C, gas mark 4.
Zest the orange and set aside. Tip the plums into a medium ovenproof dish then scatter the caster sugar, orange juice and sloe gin over the top.
Toss to combine then set aside.
Tip the flour into a large bowl with the ground cinnamon and stir together.
Coarsely grate the butter into the flour then rub together with your fingertips until the mixture resembles breadcrumbs.
Stir in the ¾ of the orange zest, the demerara sugar and porridge oats and mix until evenly distributed.
Scatter over the top of the plums in an even layer then place in the oven to bake for 40 minutes until golden and bubbling.
Meanwhile, make the caramel sauce. Heat the sugar in a pan until melted then continue to cook until light golden brown.
Whisk in the butter then stir in the cream and cook for 5 minutes until thickened and a beautiful golden colour.
Stir in the last of the orange zest.
Serve the crumble with a drizzle of salted caramel sauce.
Prep time: 20 mins
Cook time: 40 mins
750g plums, halved and stoned
50g golden caster sugar
1 orange, zested and juiced
75ml sloe gin
150g plain flour
1tsp ground cinnamon
160g demerara sugar
150g porridge oats
100g golden caster sugar (for caramel sauce)
75g salted butter (for caramel sauce)
200ml whipping cream (for caramel sauce)