Preheat oven to 350°. Grease and flour three 9-in. round baking pans.
In a medium bowl, combine flour and baking soda. This is the dry mixture.
In a stand mixer bowl, cream butter, shortening and granulated sugar until light and fluffy.
Add in egg yolks and vanilla then mix evenly.
Alternatively, add in the dry mixture and buttermilk. Beat until just combined.
Stir in coconut and pecans.
In another bowl, beat egg whites with clean beaters until stiff but not dry. Add the egg whites little by little into the batter and mix with a rubber spatula.
Divide the batter evenly into the prepared pans.
Bake until a toothpick inserted in center comes out clean, 20-25 minutes.
Cool the pans 10 minutes on a wire rack. Then invert it from the the cake pans. Cool completely before frosting the cake.
CREAM CHEESE FROSTING
In a stand mixer bowl, beat the cream cheese and butter until smooth.
Beat in confectioners’ sugar and vanilla until fluffy.
Stir in pecans. Spread frosting between layers. Then frost the frosting all over the cake. Refrigerate.