1 (18 1/2 oz.) pkg. yellow cake mix
2 c. sugar
1 (16 oz.) carton sour cream
12 oz. coconut
1 1/2 c. frozen whipped topping, thawed

Prepare cake mix according to package directions making 2 (8 inch) layers; when cool split both layers. Combine sugar, sour cream and coconut; blending well. Chill, reserve 1 cup sour cream for frosting. Spread remainder between layers of cake.

Combine reserved sour cream mixture with whipped topping; blend until smooth; spread on top and sides of cake; seal cake in an airtight container and refrigerate for 3 days before serving.