Preheat oven to 350°F (175°C).

Grease and flour three 9-inch round cake pans.

Melt chocolate and water in a saucepan over low heat, stirring until smooth.

Combine flour, baking soda, and salt in a separate bowl.

Cream margarine and sugar until light and fluffy.

Beat in egg yolks one at a time, then stir in melted chocolate and vanilla.

Alternate adding dry ingredients and buttermilk to the creamed mixture, beating until smooth.

Beat egg whites until stiff peaks form.

Gently fold egg whites into the batter.

Pour batter evenly into prepared pans.

Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean.

Let cool in pans for 10 minutes before inverting onto a wire rack to cool completely.

Frost with Coconut-Pecan Frosting.