Pour the melted salted butter into an 8-inch square baking dish, spreading it evenly across the bottom. Do not stir the butter with the batter.
Prepare the batter.
In a medium mixing bowl, combine 1 cup granulated sugar and the self-rising flour. Stir until evenly mixed.
Add the milk and vanilla.
Add the whole milk and vanilla extract to the flour mixture. Stir until the batter is well combined and smooth.
Add the batter to the dish.
Pour the batter evenly over the melted butter in the prepared baking dish. Do not stir.
Prepare the blackberries.
In a clean mixing bowl, combine the fresh or frozen blackberries with the remaining ½ cup granulated sugar. Stir gently until the berries are evenly coated.
Add the blackberries.
Spoon the sugared blackberries evenly over the batter. Do not stir the berries into the batter.
Bake the cobbler.
Bake for 50 to 60 minutes, or until the top is golden brown and the fruit is soft and bubbling.
Cool slightly.
Remove the cobbler from the oven and allow it to cool for 10 to 15 minutes before serving.
Serve.
Serve warm, preferably with vanilla ice cream if desired.
Notes
To make this recipe gluten-free, replace the self-rising flour with a gluten-free self-rising flour blend.If gluten-free self-rising flour is not available, combine 1 cup gluten-free all-purpose flour blend, 1 ½ tsp gluten-free baking powder, and ½ tsp salt.Confirm that the granulated sugar, whole milk, vanilla extract, salted butter, and blackberries are gluten-free.Use certified gluten-free vanilla extract and baking powder if preparing this recipe for someone with celiac disease or severe gluten sensitivity.Check frozen blackberries for any cross-contamination warnings or added ingredients.Use clean mixing bowls, measuring cups, spoons, baking dish, and serving utensils to prevent cross-contamination.Serve with certified gluten-free vanilla ice cream, whipped cream, or fresh berries.