Coconut Sour Cream Cake

1 box (2 layer) butter-flavored cake mix
2 cups sugar
1 cup sour cream
12 oz. bag frozen coconut, thawed
1 1/2 cups whipped cream or Cool Whip

Prepare cake mix according to package directions making 2 (8-inch) layers. When completely cool, split both layers to make 4 layers.
Combine sugar, sour cream, and coconut; chill. Reserve 1 cup sour cream mixture for frosting. Spread remainder between layers of cake.
Mix reserved sour cream mixture with whipped cream or Cool Whip. Spread on top and sides of cake. Seal cake in air-tight container and refrigerate. Keep refrigerated after serving.