Preheat the oven to 350 ° F (175 ° C). Grease a baking dish.
In a large bowl, stir together brown sugar, oatmeal, flour and butter. Mix until lumpy consistency. Cover the bottom of the dish with half of this mixture. Place the berries on the oatmeal mixture. Cover the berries with the remaining mixture. Sprinkle ½ cup sugar and cinnamon over it.
Bake in preheated oven for 40 to 45 minutes, until apples are tender and garnish is browned.