Ingredients
1 cup rolled oats
1 cup brown sugar
3/4 cup all-purpose flour, divided
1/2 cup butter, softened
4 cups fresh blackberries
Preparations
Preheat the oven to 350 degrees F (175 degrees C).
Combine oats, brown sugar, and 1/2 cup flour in a bowl. Cut in butter with 2 knives or pastry blender until the mixture is moistened and crumbly.
Spread blackberries into an 8-inch square baking dish. Sprinkle with remaining 1/4 cup flour and toss well to coat. Sprinkle oat mixture over top.
Bake in the preheated oven until golden brown, 35 to 40 minutes.