Stir the ingredients for the blackberry filling together in a bowl until well combined. Transfer the filling mixture to a small casserole dish or 8" x 8" cake pan.
Prepare the Cobbler Topping:
Stir the ingredients for the topping together in the same bowl you used for the filling. Evenly spread it over the blackberries in the casserole dish and bake in the oven for 30 to 40 minutes, until the topping is golden-brown and the blackberries have softened and become bubbly.
Serve blackberry cobbler with choice of dairy-free ice cream or whipped cream.