How to make it :
Stir together just the berries and sugar in a large bowl and let it sit out for 25-30 minutes. Preheat oven to 375. Stir together the flour, baking powder, salt, and milk with a wooden spoon.
Next, stir in the melted butter and hand-mix it until the ingredients are well incorporated and you have few clumps. Pour batter into medium baking dish and smooth it out.

You can choose to line it with parchment paper or not, but don’t grease the pan. Finally, pour the macerated blackberries on top with all the sugar included and evenly distribute it over the batter.
Bake for 45 minutes to an hour, depending on how golden you prefer it to be. Let it cool for 5 minutes so it will hold its shape.