1 (18 1/2 oz.) pkg. butter flavored cake mix
1 1/2 c. sugar
1 (16 oz.) carton sour cream
1 (12 oz.) coconut
1 1/2 c. Cool Whip

Prepare cake mix according to package directions. Make 2 layers. When completely cool, split both layers.

Combine sugar, sour cream and coconut, blending well. Chill. Reserve 1 cup sour cream mixture for frosting. Spread remainder between layers of cake.

Combine reserved sour cream mixture with Cool Whip, blending until smooth. Spread on top and sides of cake. Seal cake in airtight container and refrigerate for 3 days before serving.