Spray a 7.6 x 10.6 baking dish with nonstick spray and preheat the oven to 375 degrees F.
Add the berries into the baking dish.(do not defrost the berries)
squeeze the juice of 1 lemon over the berries.
Add the cornstarch into the baking dish and then mix all of the ingredients up until you can't see the white of the cornstarch anymore.
Sprinkle white cake mix over the berries and even it out with your hands.
Place the pats of butter over the cake as evenly as you can to cover most of the cake mix. (Do not mix)
Bake at 375 degrees F. for about 1 hour or until golden and bubbly.
Now try not to eat half the cake by yourself like I did! LOL Make it!!!