Preheat the oven to 350 degrees F.Grease and base line two 8-inch sandwich tins.Mix the sugar, flour, salt and cocoa powder together in a large bowl.Rub in 1 stick butter.Beat the eggs, milk and vanilla.Add to the bowl, stir well, and pour into the tins.Bake for 25-30 minutes.Cool on a wire rack.Beat the powdered sugar with the remaining butter until light and creamy.Use half to sandwich the cakes together, then spread the rest over the top. Decorate with crumbled chocolate flakes.
Source : The Best of Billington’s Recipe Collection 2