Preheat the oven to 350 degrees F. Spray 2 (9-inch) round cake pans with cooking spray; set aside.
In a large mixing bowl, combine the cake mix and pudding mix. Add the egg whites, milk, and oil; beat with an electric mixer on low for 30 seconds. Scrape down the side of the bowl. Beat on medium for 2 minutes more. Fold in the drained blueberries. Divide the batter evenly between the prepared pans.
Bake for 35 to 40 minutes or until a toothpick inserted near centers comes out clean. Cool in pans on a wire rack for 10 minutes; remove from pans. Cool completely on wire rack.
For white frosting:
In a medium bowl, combine the vanilla frosting and melted white baking chips. Set aside 1 1/2 cups white frosting.
To assemble, place one cake layer on a serving plate. Spread with 1/2 cup white frosting, then top with second cake layer. Frost the side and the top of the cake with the remaining white frosting.
In a medium bowl, beat the powdered sugar and the reserved 1 1/2 cups white frosting on low until combined.
To decorate, insert a basket weave decorating tip into a pastry bag and fill with the powdered sugar-white frosting mixture. Starting on the far left edge of the cake top, pipe a long stripe of icing straight across top of the cake. Cover the cake top with additional stripes, spaced 1/4 inch apart. Turn the cake 45 degrees; pipe additional stripes of icing across the original strips, spaced 1/4 inch apart. Pipe a border around top edge of the cake. Garnish the cake with fresh blueberries.
Excerpted from the book, Sandra Lee Bake Sale Cookbook, by Sandra Lee