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

Prepare cake mix according to directions, making 2 (8-inch) layers. Cook and let cool. Split horizontally. Blend together sugar, sour cream and coconut. Spread all except for 1 cup of this mixture between the layers. Blend the remaining cup of mixture with the Cool Whip and spread on top and sides of cake. Seal in airtight container and refrigerate for 3 days before serving.