1 (12 oz.) pkg. frozen coconut
1 1/2 c. powdered sugar
8 oz. sour cream
1 lg. Cool Whip
1 box Duncan Hines butter cake mix

Mix coconut, powdered sugar and sour cream. Set in refrigerator. Bake a 2 layer cake according to package directions. Cool completely. Split 2 layers into 4 layers. Put filling between layers, but not on top. Cover completely with Cool Whip. Let set in refrigerator for 24 hours in a tightly sealed container.