Let eggs stand at room temperature for 30 minutes. Line a greased 13-inch by 9-inch baking pan with waxed paper. Grease and flour the paper; set aside. In a microwave, melt chocolate with water; stir until smooth. Cool. In a large bowl, cream butter and sugar until light and fluffy. Add egg yolks, one at a time, beating well after each addition. Beat in chocolate mixture and vanilla. Combine the flour, baking soda and salt; add to creamed mixture alternately with buttermilk, beating well after each addition. In a small bowl with clean beaters, beat egg whites until stiff peaks form; fold into batter. Spread batter evenly into prepared pan. Bake at 350° for 50-55 minutes or until a toothpick inserted near the center comes out clean. Cool for 10 minutes before inverting onto a wire rack to cool completely. Remove waxed paper. For frosting, in a heavy saucepan, combine the milk, sugar, egg yolks and butter Cook and stir over medium-low heat until thickened and a thermometer reads 160° or is thick enough to coat the back of a metal spoon. Remove from the heat. Stir in the coconut, pecans and vanilla. Beat on high until frosting is cool and achieves spreading consistency. Place cake on a serving platter; frost top and sides of cake.