In small mixing bowl - mix flour, salt and soda - set aside
In saucepan - heat, stir chocolate and water till chocolate melts. Remove from heat and cool
In large mixing bowl - beat butter for 30 seconds. Beat in the sugar till fluffy. Beat in egg yolks, one at a time, beating well after each. Beat in chocolate and vanilla.
Alternate add the flour mixture and buttermilk, beating on low speed after each addition. Wash the beaters thoroughly.
In med bowl, beat egg whites on high till stiff peaks form. Fold whites into batter. Divide the batter into 2 greased and flour cake pans.
Bake at º350 for 30-35 minutes or till toothpick inserted comes out clean. Cool 10 minutes in pans then on wire racks.
In saucepan, combine 1 C evaporated milk, sugar, egg yolks and butter. Cook and stir till slightly thickened and mixture just bubbles. Stir in vanilla, coconut and pecans.
Place 1 cake on plate and spread with 1/3 of the topping. Top with second cake layer and the remaining layer of cake. Chill until ready to serve.