Cover the bottom of baking ... the can of blueberry pie filling. Then sprinkle DRY the box of cake mix and dot with the butter ... center comes out clean.
Spread blueberries in bottom of a 9 x 13 inch (ungreased) cake pan. Spoon pineapple over blueberries. ... on dry cake mix. Drizzle melted butter over ... degrees for 30-40 minutes.