12 oz. sour cream
2 c. granulated sugar
8 to 10 oz. coconut
1 butter recipe yellow cake mix
1 lg. container Cool Whip

Day 1: Mix sour cream, sugar and coconut. Seal and refrigerate for 24 hours. Day 2: Bake cake mix according to package directions. Cool. Slice lengthwise, making 4 layers. Put layers together with filling made on day one. Put filling on top also. Frost entire cake with Cool Whip. Sprinkle with additional coconut if desired. Store in airtight cake saver and refrigerate for 3 days before serving.