1 Duncan Hines yellow butter cake

Prepare according to directions (2 layers). Cool.

Mix and chill:

2 c. sugar
1 pt. sour cream
2 pkg. frozen coconut (Tom Thumb)
:
1 1/2 c. Cool Whip

After cake is cool cut to make 4 layers. Reserve 1 cup of coconut mixture. Spread the rest between the layers. Add 1 remaining cup of mixture to 1 1/2 cups Cool Whip. Ice top and sides. Cover and refrigerate for 3 days before serving.