Grease two deep 20cm cake tins and line the base with grease proof paper .

Sift flour, salt ,cocoa ,bicarbonate of soda and the sugar into a mixing bowl .

add the vinegar to the evaporated milk .

pour in the melted butter or margarine and half of the soured milk . Beat well for two minutes .

add remaining ingredients and beat for a further two minutes .

pour into the prepared tins to bake in a moderate oven ( 180'C ) for 35 minutes .

cool slightly before removing from the tins .

when totally cooled you can place whipped cream in between the two cake layers ,and frosting on top or cream to decorate .