GREASE a 1-quart baking dish; ADD blackberries.
In a small bowl, COMBINE sugar, cornstarch, water and lemon juice; STIR until smooth; POUR over berries.
In a small bowl, COMBINE oats, flour, brown sugar and cinnamon; CUT in butter until crumbly; SPRINKLE over berries.
BAKE, uncovered, at 375° until filling is bubbly, about 20-25 minutes.
Serve warm with ice cream.
Per Serving (excluding unknown items): 497 Calories; 24g Fat (43.4% calories from fat); 5g Protein; 67g Carbohydrate; 3g Dietary Fiber; 62mg Cholesterol; 247mg Sodium. Exchanges: 2 Grain(Starch); 0 Fruit; 5 Fat; 2 1/2 Other Carbohydrates.