Lemon Blueberry Dump Cake - so easy and SOOOO delicious! Blueberries, sugar, lemon zest, lemon cake mix and butter. Just dump everything in the pan and throw it in the oven. No mixing, no extra dirty dishes, no spoons, just one pan. Great for potlucks and cookouts. Serve warm with vanilla ice cream. There are NEVER any leftovers! SO good!