Melt chocolate over hot, not boiling water. Cool slightly. Cream butter and sugar until light and fluffy. Add cooled chocolate. Add eggs, one at a time, beating well after each addition. Sift dry ingredients together and add alternately with buttermilk. Beat only enough to blend. Fold in beaten egg whites, vanilla, pecans and coconut. Pour into a 9x13 pan or 2 8" round pans. Bake at 350~ for 40-45 minutes or until done. WHITE CHOCOLATE ICING: In medium saucepan combine melted chocolate and flour. (all-purpose). Blend in milk, cook over medium heat, stirring constantly until thick. Cool completely. In large mixing bowl cream butter, sugar and vanilla. Beat until light and fluffy. Gradually add completely cooled chocolate mixture. Beat to blend well, but over-beating will break it down soupy. ----