Melt the butter in the warm buttermilk (I melted the butter with a quick zap in the microwave)

Put the flour, sultanas and salt in a bowl, gradually pour in the buttermilk mixture and beat well. Leave this mixture to stand for a few hours, if possible

When ready to bake the cake, beat the eggs, add the sugar, soda and vinegar and then pour this second mixture into the first one, beating well

Pour all the mixture on to a greased, moderately hot bakestone to make one large cake. Bake and turn as for pancakes

Then split in half while warm and spread with butter