01 -
Heat the oven to 350°F and prepare three nine-inch cake pans with greased parchment bottoms.
02 -
Melt the chopped white chocolate gently and cool until no longer hot.
03 -
Whisk flour, baking soda and salt together.
04 -
Beat butter and sugar until creamy, then add the four cake yolks individually. Mix in white chocolate and vanilla.
05 -
Alternate dry ingredients with buttermilk at low speed.
06 -
Beat the four whites in a clean bowl to medium-stiff peaks and fold into the batter in two additions.
07 -
Divide among pans and bake about twenty to twenty-two minutes, continuing until the centers are set and a tester has no wet batter.
08 -
Cool briefly in pans, then on racks. Toast pecans until fragrant, watching closely.
09 -
Stir evaporated milk, both frosting sugars, frosting butter and five yolks over moderate heat until thickened and 160°F.
10 -
Remove from heat and stir in pecans, coconut and frosting vanilla.
11 -
Cool to spreading consistency and refrigerate within two hours. Stack fully cooled layers with frosting between them and over the exterior, then refrigerate.