In a large mixing bowl, first combine all the dry ingredients, including the pinch of salt, then add the raisins, the grated apples and the grated lemon zest.
Stir thoroughly to combine everything well. Now beat the egg into the milk and stir the whole lot into the mixture. Pack the mixture into the pudding basin, cover the basin tightly with a sheet of baking parchment, then with a sheet of foil make a pleat in the centre and secure with string.
After that, boil a kettle and pour the boiling water into a saucepan, about half full, place it on a medium heat and, when it comes back to the boil, fit a steamer over the top. Steam the pudding for 2 hours, checking the water level in the saucepan now and then.
Serve with custard, or at Christmas with rum butter. You can watch how to make Poper Custard in our Cookey School Video on this page.
You will also need a 2 pint (1.2 litre) pudding basin, well buttered, some baking parchment, kitchen foil, and some string.