Combine the cocoa and 1 cup of boiling water in a bowl and cool completely. Sift the flour, baking soda and salt together and set aside. Cream the shortening together in a mixing bowl until light and fluffy, using an electric mixer set on medium speed. Add the egg yolks and beat well. Blend in the vanilla extract. Add the dry ingredients alterantely with 1 cup of cold water to the creamed mixture, beating well after each addition, using an electric mixer set at low speed. Blend in the cooled cocoa mixture. Using another bowl, beat the egg whites until stiff peaks form, using clean beaters, on an electric mixer set at high speed. Fold the egg whites into the chocolate mixture until no white streaks show. Pour the batter into a greased 13 X 9 X 5 cm baking pan. Bake in a preheated 190ºC . oven for 30 to 35 minutes or until the cake tests done. Cool the cake completely, in the pan on a wire rack. When cold, spread the cake with the Pineapple topping and drizzle with the cocoa Icing. PINEAPPLE TOPPING: Combine the cornstarch, sugar and salt in a 2 litre saucepan. Add the pineapple and juice. Cook over medium heat, stirring constantly, until the mixture boils. Remove from the heat and cool completely. COCOA ICING: Combine the confectioners' sugar, cocoa, and milk in a bowl and beat until smooth. From The Farm Journal's Complete Home Baking Book Copyright 1979