To toast the pecans, lay in a single layer on a standard cookie sheet. Toast in a 350°F oven for 6-8 minutes, then cool.
Icing - In a heavy bottomed saucepan over medium high, melt the butter with the milk, granulated and brown sugar, corn syrup and salt.
Cook until the sugars have dissolved, then lower the heat to medium.
Whisk 1/4 cup of the warm liquid into the egg yolks to temper, then whisk the egg yolks into the saucepan.
Cook over medium stirring until thickened around 12-15 minutes. The consistency should coat the back of a spoon like a thin pudding. [Tip: The icing will thicken more as it cools]
Remove from the heat and add the vanilla, toasted pecan pieces and coconut. Pour into a bowl and cool to room temperature to thicken before frosting cake.
Yield: filling and icing for 1 (9) inch 3-layer cake, 9 x 13-inch sheet cake or 24 cupcakes
To make the cake: Oven preheated to 350°F. Cover the bottoms of 3 (9-inch) round pans with waxed paper; and spray sides with cooking spray.
Microwave the chocolate and water in a large microwaveable bowl on HIGH 1-1/2 to 2 minutes or until chocolate is almost melted, stirring after 1 min. Stir until chocolate is completely melted.
Beat egg whites in small bowl with mixer on high speed until stiff peaks form; set aside.
Mix flour, baking soda and salt. Beat butter and sugar in large bowl with mixer until light and fluffy.
Add egg yolks, 1 at a time, beating well after each. Blend in melted chocolate and vanilla.
Add flour mixture alternately with buttermilk, beating until well blended after each addition.
Add egg whites; stir gently until well blended. Pour into prepared pans.
Bake for 30 minutes or until a toothpick inserted in centers comes out clean. Immediately run small spatula around cakes in pans. Cool cakes in pans 15 minutes then remove from pans to wire racks. Cool completely.
Spread the coconut-pecan filling and icing between the cake layers and onto top of cake.
The recipe makes enough icing to frost the cake completely, if desired.