1 pkg. (18 1/2 oz.) butter flavor cake mix
2 c. sugar
1 (8 oz.) sour cream
1 pkg. (12 oz.) frozen coconut, thawed
1 1/2 c. Cool Whip

Prepare the cake according to directions, making 2 (8 inch) layers. Split both layers horizontally after they have cooled. Blend together the sugar, sour cream and coconut; chill. Spread all but 1 cup of the sour cream mixture between the 4 layers. Blend the remaining cup of the mixture with th cool Whip and spread on the sides and top of the cake. Seal in an airtight container and refrigerator for 3 days before serving. Keep refrigerated after cutting.