Preheat oven to 350°F (175°C). Grease and flour three 8-inch round cake pans.
In a large bowl, cream together the butter and sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla.
Combine the flour and baking soda, add to the creamed mixture alternately with buttermilk. Stir in the coconut and pecans. Pour batter into the prepared pans.
Bake in the preheated oven for 25 to 30 minutes, or until a toothpick inserted into the center of the cake comes out clean. Allow to cool.