1Scald milk in double boiler. Mix cocoa and sugar together, dissolve in some of the scalded milk, and then add the rest. Moisten cornstarch with a little cold milk and thicken boiling liquid, add in the salt into the mixture, taking care not to let the egg touch the side of the pot. Remove from fire and add vanilla.
2Break cake into a pudding dish and pour the hot custard over it, stirring it well together. When cold cover with whipped cream, sweetened and flavored to taste.