Preheat oven to 350 degrees F (175 degrees C). Grease and flour 4 - 9 inch round pans. Melt the chopped German chocolate in 1/2 cup hot water, and set aside.
In a large bowl, cream together the 2 cups sugar and shortening. Beat in 4 egg yolks until smooth. Next, stir in the buttermilk and vanilla. Sift together the flour, salt and baking soda; mix into creamed mixture. Then, stir in the melted chocolate. In another bowl, whip egg whites to stiff peaks, fold into the batter. Divide the batter evenly between the four pans, and spread evenly.
Bake for 20 to 25 minutes in the preheated oven. Cool cake in pans on wire racks. When cool, fill and ice with the coconut pecan icing.
To make the icing: In a medium bowl, whip 1 egg yolk, heavy cream and 1 1/4 cup sugar until smooth. Cook in the top of a double boiler, until the mixture thickens. Remove from heat and stir in the coconut, pecans and butter. Cool before icing the cake.