1Bake in 2 pans following the box directions when cool slice into 4 layers.
2Mix sour cream, coconut, and sugar. Reserve 1 cup for Iceing . Use the sour cream, coconut, sugar mixture between layers.
Mix the reserved cup of icing with the cool whip. Ice cake with this mixture. Then refrigerate.
3Note: filling and icing will be better if made a day ahead.