Blueberry Cake - cooking recipe

Ingredients

1 butter recipe cake mix
1 can blueberry pie filling
1 (8 oz.) carton sour cream
13 oz. Cool Whip
1/2 tsp. vanilla

Preparation

Cook cake mix as directed on package. Cool.
Combine sour cream, Cool Whip and vanilla.
Frost cake with this mixture.
Put pie filling on top of cake.
Refrigerate.