Grease and flour two 9-inch round baking pans; set aside.
In a large mixing bowl, cream the butter and shortening until blended. Add in the sugar and beat until fluffy.
Beat in the egg yolk. Beat until well blended; about 1-2 minutes.
Add the cake flour and baking soda alternately with the buttermilk. Add in the vanilla; mix for 1 minute. Stir in the coconut and pecans.
In another bowl, mix egg whites until stiffly beaten. Fold egg whites into the cake batter.
Divide the cake batter into the prepared pans.
Bake for 25 minutes or until toothpick inserted in center comes out clean. When done, remove from oven and cool cake in the pans for 5-10 minutes; remove cake and cool completely on wire rack. Frost the cake with cream cheese frosting.
Cream Cheese Frosting:
In a medium bowl, mix the cream cheese and butter until blended.
Add the powdered sugar and vanilla and beat until light and fluffy.