Preheat the oven to 180 C / Gas 4. Grease two 450g loaf tins or use a disposable paper liner or case.
In a large bowl, cream together the butter and the sugar either by hand or using an electric mixer until the mixture is pale and light and fluffy.
Slowly add the eggs and incorporate fully into the mix.
In another bowl, sift together the flour, salt, bicarbonate of soda and baking powder. Then pour into a measuring jug the milk and lightly whisk in the vanilla extract.
Add the dry and wet ingredients in stages (try to finish with the dry) to the egg mixture and mix well. You may not require all the milk or you may require a bit more. You are looking for a ribbon consistency when using a spoon. If using a hand mixer or stand mixer, scrape around the bowl and mix the last bits in by hand to ensure you have it all incorporated.
Tip or spoon mixture into the waiting tins and fill to about half way as these cakes will rise in the oven.
Bake in the centre of the preheated oven until the top of the cake is a light-mid brown and a skewer comes out clean, about 40 to 60 minutes, depending on how runny your mix was. Remove from oven and allow to cool.
When cooled, slice each of the loaves horizontally, spread on the raspberry jam and sandwich the loaves back together. Try not to put too much jam in the middle as it could make the cake soggy and will not last as long.
To finish, melt the white chocolate (either using a double boiler or microwave) and coat the top and, if you like, the sides of the loaves. Allow the chocolate to harden, then serve.
This cake can either be made in loaf tins or a standard cake tin. I have also used any excess mix to make cupcakes. I find the ready to use cake liners are so useful especially if the cake is going to travel.
A lactose free version of this recipe could be possible, my lactose intolerant friends tell me that all the ingredients can be replaced with soya alternatives and would produce an equally splendid cake.
You can use any type of milk for this recipe, if you want a tangier version, use buttermilk, tangy and creamy at the same time, I make it with skimmed (non-fat) milk and it tastes as good as a full fat version. The choice is yours.