Prepare a 12-cup Bundt pan using butter and flour, or a flour spray. Set aside.
Melt the chocolate in the boiling water. Do this in a double boiler or in a small stainless steel bowl set over a pan of simmering water.
Stir the chocolate thoroughly into the water and set aside to cool.
Combine the flour with the salt and baking soda and set aside.
Cream the butter and the sugar until fluffy.
Add the egg yolks one at a time, beating well after each addition.
Blend in vanilla and chocolate.
Add the flour alternatively with the buttermilk to the sugar mixture.
Beat after each addition until smooth.
In another bowl, beat the egg whites until stiff but not dry.
Carefully fold them into the batter until the white streaks disappear.
Pour the batter into the prepared pan.
Bake for 35 to 40 minutes or until a toothpick comes out of the cake clean.
Do not be alarmed if the top has fallen slightly.
Cool in the pan for 15 minutes then invert onto a wire rack or serving plate.
Coconut Pecan Frosting:
To prepare the frosting, mix the evaporated milk, sugar, egg yolks, butter and vanilla in a saucepan and stir over medium heat until thickened. This should take between 10 and 15 minutes, depending on heat and humidity.
Stir in the coconut and nuts.
Cool until the frosting is thick enough to spread.
Putting the cake together:
When the cake is cool, slice it horizontally with a serrated knife. Aim a little higher than half way up.
Flip the top half onto a plate.
Spread 1/3 of the frosting on the bottom half and place the top half back on the frosted cake.