Cake:

1 box yellow cake mix

Bake cake as directed in two layers. Cool. Cut each layer into 2 layers.

Frosting:

8 oz. cream cheese, softened
1/2 c. granulated sugar
1/2 c. confectioners sugar
12 oz. Cool Whip
1 can blueberry pie filling

Cream cheese and sugars together. Mix in Cool Whip and about 1/4 can of blueberry pie filling. Frost between layers and sides of cake, bringing frosting onto top layer about 1/2-inch all the way around cake. Pour rest of blueberry pie filling on the top of the cake, letting a bit drip down the sides.