Gluten Free Blackberry Cobbler

Name: Gluten-Free Blackberry Cobbler
Ingredients: cooking spray; 5 cups fresh blackberries; 0.25 cup coconut sugar; 2 tablespoons gluten-free all-purpose flour mix (such as Bob's Red Mill®); 1 cup gluten-free all-purpose flour mix (such as Bob's Red Mill®); 1 cup coconut sugar; 1 cup low-fat buttermilk; 0.25 cup coconut flour; 0.25 cup melted butter; 1 tablespoon baking powder; 1 teaspoon xanthan gum; 0.5 teaspoon sea salt; 0.5 teaspoon gluten-free vanilla extract; 1 dash ground nutmeg