- 1 cup blackberries
- 1/4 cup white sugar
- 1/3 cup quick-cooking oats
- 1/4 cup brown sugar
- 1 1/2 teaspoons ground cinnamon
- 1 cup all-purpose flour
- 3/4 cup white sugar
- 1 teaspoon salt
- 1 teaspoon baking powder
- 1/4 cup milk, or as needed
- 1/4 cup butter, cut into small chunks
- Preheat oven to 350 degrees F (175 degrees C). Butter a 9×12-inch baking dish.
- Stir blackberries and 1/4 cup white sugar together in a bowl.
- Mix oats, brown sugar, and cinnamon together in a separate bowl.
- Mix flour, 3/4 cup white sugar, salt, and baking powder together in a third bowl. Add milk to flour mixture; mix well. Pour batter into prepared baking dish. Top with blackberry mixture; sprinkle oat mixture over blackberries. Top oat mixture with butter chunks.
- Bake in the preheated oven until bubbling, about 30 minutes.