Rum and orange doughnuts with chocolate sauce and orange custard

By Matt Tebbutt From Saturday Kitchen Ingredients For the doughnuts. 1 unwaxed orange, zest only splash orange essence 100ml/3½fl oz dark rum 200g/7oz self-raising flour 50g/1¾oz caster sugar 50g/1¾oz unsalted butter 2 free-range eggs vegetable oil, for deep-frying 100g/3½oz caster sugar For the chocolate sauce 75g/2½oz dark …