When I lived in California where you could pick blackberries by the bucket at the roadside, I invented this recipe:
Pick 1-2 pints of the ripest, juiciest berries you can find.
Bake single-layer pie crust of choice. Let cool.
Fill with washed berries.
Make a from-scratch vanilla pudding (milk, cornstarch, vanilla).
Pour hot pudding over berries. Let set in refrigerator.