Sift the flour and the bicarbonate of soda into a large bowl and stir in the sugar (you don't need to sift the sugar).
In another mixing bowl, whisk the egg very well.
Now add the jam, vinegar, butter and milk, whisking well after adding each ingredient.
Add the wet ingredients of step 5 to the dry ingredients of step 4 and mix well with a wooden spoon.
Pour the batter into the Dutch Oven, put on the lid and bake for 50 mins at a Moderate Temperature by using Baking Method and the correct Amount Of Coals.
Don't add too much heat, as burning is a big danger.
There is no particular risk in having too little heat and taking up to 1 hour to get the baking done, so rather go too slow than too fast.
After roughly 50 mins of baking, it should be well risen and brown.
When the pudding has been baking in the Dutch Oven for about 40 mins (about 10 mins before it is done), heat all the ingredients for the sauce in a small Skillet over medium coals.
Keep stirring to ensure that the butter is melted and the sugar is completely dissolved, but don't let the mixture boil.
If you want a (slightly) less sweet pudding, use half a cup of sugar and a full cup of hot water for the sauce, instead of the other way round as per the ingredients list.
After about 50 mins of baking, insert a skewer into the middle of the pudding to test whether it's done.
If the skewer comes out clean, it's ready.
Take the pudding off the fire and turn out on to a plate pour the sauce evenly over it.
Serve the Malva Pudding warm with a scoop of vanilla ice-cream, a dollop of fresh cream or a puddle of vanilla custard.