Chocolate and caramel sponge pudding with chocolate custard

Method

1. Heat the oven to 170°C/150°C fan/gas 3½. Put the butter and 200g sugar in a large mixing bowl and, using an electric mixer, whisk for 2-3 minutes until light and fluffy. With the beaters still going, slowly add the beaten eggs, a little at a time, until fully incorporated.
2.  Sift the 50g cocoa powder and flour into the mixing bowl, then add the soured cream and 2 tbsp milk. Using a large metal spoon, gently fold everything together to combine, then fold in the caramel pieces.
3.  Spoon the mixture into the prepared baking dish and bake for 50-55 minutes or until the sponge is well risen and the top springs back to the touch.
4. Meanwhile, make the custard. Put the 570ml milk in a saucepan and heat gently over a low heat until just steaming. In a medium mixing bowl, combine the custard powder, 2 tbsp cocoa powder and 2 tbsp soft light brown sugar. Using a balloon whisk, mix in a little of the warm milk to make a paste, then slowly whisk in the rest of the milk.
5. Pour all the custard mixture back into the pan and stir continuously over a low-medium heat with a wooden spoon until the custard has thickened and starts to gently bubble. Continue to cook for 5 minutes, stirring every now and then with the wooden spoon and scraping the bottom of the pan to make sure the custard doesn’t catch (burn). Serve the warm sponge with the custard poured over.