Butter Pecan Frosting
Melt 2 tablespoons butter in a large skillet. Add pecans and cook over medium heat, stirring occasionally, until toasted – about 10 minutes. Remove from heat and cool completely.
Beat cream cheese and 1/2 cup butter at medium speed until creamy. Gradually add sugar. Beat until light and fluffy. Stir in buttered pecans and vanilla. Cover and chill at least 1 hour.
Place white chocolate in a bowl and pour boiling water over it, stirring until smooth. Set aside to cool.
Preheat oven to 350°. Grease three 9-inch round cake pans and line with wax paper. Grease and flour wax paper.
Using an electric mixer on medium speed, beat butter until creamy. Gradually add sugar, beating well. Add egg yolks, one at a time, beating after each addition. Stir in melted white chocolate and vanilla.
Combine buttermilk and baking soda. Add flour to butter mixture, alternating with buttermilk mixture. Begin and end with flour. Mix at low speed after each addition until blended.
Beat egg whites to stiff peaks. Gently fold into batter. Pour batter evenly into prepared pans.
Bake for 20-22 minutes, or until a toothpick inserted in the center of cake comes out clean. Cool in pans for 10 minutes. Then, remove from pans to wire racks to cool completely.
Spread frosting between layers and on the top and sides of cake. Garnish, if desired.
Store in refrigerator.