1. Preheat ovem to 375.
2. Rinse berries.
3. In a food processor, pulse flour, brown sugar, butter and salt until combined.
4. In a large bowl, toss together blackberries, tapioca, granulated sugar, orange zest and orange juice.
5. Pour blackberry mixture into a 2-quart baking dish.
6. Sprinkle evenly with flour mixture.
7. Bake until topping is golden and juices are bubbling, about 50 minutes.
Let cool 20 minutes, serve warm or at room temp.