-
Preheat oven to 350 degrees F. Grease and flour 3 8-inch round cake pans lined with parchment paper.
-
Separate eggs and allow to come to room temperature.
-
Combine baking soda and buttermilk. Set aside.
-
Whisk together cake flour and salt. Set aside.
-
Using mixer (I use paddle attachment), cream butter, shortening, and sugar on medium-high speed until light and fluffy, about 3 to 5 minutes.
-
Add egg yolks one at a time, beating well after each addition.
-
Add vanilla and beat until smooth.
-
Add flour and buttermilk alternately with mixer on LOW speed, beginning and ending with flour, and mix until just combined.
-
Add coconut and pecans with mixer on LOW speed, and mix until just combined.
-
Transfer batter to a medium size bowl and wash mixing bowl thoroughly to use for egg whites.
-
With whisk attachment, beat egg whites until stiff peaks form.
-
Add 1/3 egg whites to batter and fold with spatula to loosen batter. Fold in the remaining egg whites to the batter.
-
Divide batter among the 3 prepared pans and spread it out evenly.
-
Bake until a toothpick comes out clean, or about 20-22 minutes. Remove and let cool in pans for about 10 minutes, then remove from pans to cool completely.