Blackberry Cobbler

1.Preheat oven to 350 degrees.
2.For the filling, toss together berries, 3/4 cup sugar, tapioca, 1/2 teaspoon salt, and orange juice in a large bowl. Transfer berry mixture to a 2 1/2-qt. rectangular or oval baking dish (about 2 inches deep).
3.For the crust, combine flour, baking powder, and 1/4 teaspoon salt in a small bowl; set aside.
4.Cream butter and 1 cup sugar in a large bowl with a mixer on medium speed until light and fluffy, 3-5 minutes.
5.Add eggs, vanilla, and zest; beat on medium speed until combined, then beat in flour mixture until a moist dough forms. Spoon dough over berries.
6.Bake cobbler until juices are thick and bubbly and topping is golden brown, about 1 1/4 hours. Cool cobbler on a rack at least 1 hour. Serve cobbler with ice cream, if desired.