Preheat your oven to 375 degrees F (190 degrees C).
In a bowl, combine the blackberries, 1/2 cup of the sugar, and lemon juice. Stir until the sugar is fully dissolved.
In a separate bowl, combine the flour, baking powder, salt, and remaining sugar.
Add the milk to the dry ingredients, stirring just until the dry ingredients are moistened. Lumps are ok.
Pour the melted butter into an 8- or 9-inch baking dish. Spoon the sugared blackberries evenly over the butter.
Pour the batter over the blackberries, but do not stir. Rearrange a few of the blackberries for even distribution on top and the final cobbler will be prettier.
Bake in the preheated oven for 45-50 minutes or until the top is golden brown and the blackberries are bubbling.
Allow it to cool for a bit, then serve warm, preferably with a scoop of vanilla ice cream or a dollop of whipped cream.
Video
Notes
If using frozen blackberries, let them thaw at room temperature for 30 minutes before starting or else bake the cobbler for about 10 minutes longer (covering with foil to prevent it getting too dark).