1 pkg. butter flavored cake mix (18 1/2 oz.)
2 c. powdered sugar
8 oz. carton sour cream
12 oz. lg. frozen coconut, thawed
1 bowl of Cool Whip, sm. size

Prepare cake according to directions and make in two layers. Split both layers horizontally after they have cooled. Blend together sugar, sour cream and coconut and chill. Spread all but 1 cup of sour cream mixture between the 4 layers. Blend the remaining cup of mixture with the Cool Whip and spread on top and sides of cake and seal in airtight container.