Cream butter until it's like a thick cream. Add sugar a little at a time creaming after each addition until mixture is light and fluffy. Separate egg whites and yolks. Add well beaten yolks to mixture and blend well. Add enough hot water to cocoa to make a smooth paste, then add enough more to make 1 cup of cocoa mixture. Add to the creamed mixture. Sift together the flour, soda and salt and add alternately with the sour milk to which the vanilla has been added. Mix thoroughly. Fold in the stiffly beaten egg whites. Turn into greased tin and bake at 190 deg. Celsius for 30-40 minutes.
When cool, slice 2 inches off the top for shaping into cock size of your choice, and decorate with icing.
Cock Icing
Stir ¼ cup sugar and 1/3 cup water over moderate heat until sugar dissolves. Bring to boil then cool. Beat 115 grams butter until creamy and gradually beat in the sugar syrup a little at a time. Gradually add 85 grams of melted dark chocolate to butter mixture and beat.
Repeat the above with white chocolate for remainder of cake.