Preheat Oven: Preheat the oven to 350 degrees F. Use unsalted butter to generously grease a cast iron skillet or baking dish and set aside.
Prep Berries: Add berries to a medium-sized bowl and add lemon juice, 2 teaspoons of sugar, vanilla extract, cinnamon, and ground ginger. Mix.
Prep Batter: Add flour, baking powder, salt, sugar, and cinnamon to a bowl. Whisk well. Add milk and mix until just combined.
Assemble: Add all but 1/4 cup of the blackberries to the greased cast iron. Spread in an even layer. Dollop the thick batter to the top of the berries and gently spread while being careful to not mix batter and berries. Top the batter with the remaining 1/4 cup of blackberries.
Bake: Add to oven and bake for 35 minutes.
Serve and enjoy with vanilla ice cream!