2 qts. blackberries
2 tbsp. flour
2 sticks butter
2 tbsp. cornstarch
3 c. sugar
1 tbsp. vanilla
1 box yellow cake mix

Mix cake mix and melted butter (1 stick). Put aside. Mix cornstarch and a little water. Put aside. In a saucepan, mix blackberries, sugar, flour, vanilla and 1 stick butter. Cook over medium heat. Stir often or it will burn on bottom. When sugar, flour and butter is dissolved, pour in cornstarch mixture slowly while stirring. Let cook a little longer, until it thickens a little. Pour mixture into baking dish. Take cake mixture and crumble on top. Place in 350 degree preheated oven and cook for 35 to 45 minutes or until cake on top is golden brown.