Self-saucing Jaffa pudding

Name: Self-saucing Jaffa pudding
Prep time: 35 min
Cook time: 30 min
Total time: 1 h 5 min
Cuisine: British
Ingredients: 100g butter, melted, plus a little extra for the dish; 250g self-raising flour; 140g caster sugar; 50g cocoa; 1 tsp baking powder; zest and juice 1 orange; 3 eggs; 150ml milk; 100g orange milk chocolateor milk chocolate, broken into chunks (we used Divine orange milk chocolate); single creamor ice cream, to serve; 200g light muscovado sugar; 25g cocoa