Preheat your oven to 375F and grease a 9-inch baking dish with cooking spray. Set it aside.

In a large bowl, combine the blueberries, 1/4 cup sugar, orange juice, and orange zest. Mix gently to coat the blueberries well. Pour this mixture into the prepared baking dish and spread it out evenly.

In another bowl, whisk together the gluten-free flour, remaining sugar, baking powder, and salt. Add the cold butter cubes and use a pastry cutter or your fingers to blend until the mixture looks like coarse crumbs. Gradually add the sour cream, stirring until the dough forms.

Drop spoonfuls of the dough over the blueberry mixture, spreading them out as evenly as you can.

Bake for 30-35 minutes, until the top is golden brown and the blueberries are bubbling.

Let the cobbler cool for a few minutes before serving.