1 pkg. butter flavored cake mix
2 c. sugar
1 (16 oz.) carton sour cream
1 (12 oz.) pkg. frozen coconut, thawed
1 1/2 c. frozen whipped topping, thawed

Prepare cake according to directions on package. Make 2 (8 inch) layers; when completely cool, split both layers. Combine sugar, sour cream and coconut blending well. Chill. Remove 1 cup sour cream mixture for frosting; spread remainder between layers of cake. Combine reserved sour cream mixture with topping, blend smooth. Spread on top and sides. Seal cake in airtight container and refrigerate for 3 days before serving.