1In ungreased 8-inch square (2-quart) glass baking dish, place blueberries, raspberries and lemon juice. Microwave uncovered on High 4 to 6 minutes, stirring once, until thawed.
2In small bowl, mix sugar and cornstarch. Pour sugar mixture over berries; stir to coat berries. Microwave berries uncovered on High 10 to 12 minutes or until fruit is bubbling all over and mixture is thickened.
3In medium bowl, mix cereal and cinnamon. Stir in butter until well mixed. Sprinkle over berries. Serve warm or at room temperature with ice cream.