Treacle pudding with vanilla custard

1.Preheat oven to 150C. Pour treacle into a buttered 1.2-litre ceramic heatproof bowl or dish, or a pudding mould and set aside. Beat butter and sugar in an electric mixer until pale and creamy (2-4 minutes). Sieve flour and baking powder over butter, then add egg and milk alternately, a little at a time, and beat until smooth. Transfer to prepared dish, smooth top and cover directly with a round of baking paper. Cover with foil, secure with kitchen string to prevent water seeping in and place in a large roasting pan. Add enough boiling water to come halfway up the sides of the dish and bake until puffed and golden, or a skewer inserted withdraws with moist crumbs only (about 1¾ hours; add more water if necessary).

2.Meanwhile, for vanilla custard, place vanilla bean and seeds, cream and milk in a saucepan over medium heat and bring just to the boil. At the same time, whisk egg yolks and sugar in a bowl until very thick and pale. Carefully pour hot cream mixture over egg mixture, stirring continuously, then transfer to a clean pan. Cook, stirring continuously, over low-medium heat until mixture thickly coats the spoon (10-12 minutes). Strain into a bowl placed over ice and cool completely or serve the custard warm.

3.Turn hot pudding out onto a plate, drizzle with extra treacle and serve with custard.