1Heat oven to 350°F. Grease bottom and sides of 9-inch square pan with shortening or cooking spray. In large bowl, mix 2 cups cereal and the orange juice; let stand about 2 minutes or until cereal is soft.
2Stir oil, egg and bananas into cereal mixture. Stir in remaining cake ingredients. Spread in pan.
3Bake 35 to 40 minutes or until top springs back when touched lightly in center. Meanwhile, place 1/2 cup cereal in resealable food-storage plastic bag or between sheets of waxed paper; coarsely crush with rolling pin. In small bowl, mix crushed cereal and remaining topping ingredients until crumbly.
4When cake is done, set oven control to broil. Sprinkle topping evenly over warm cake. Broil with top about 5 inches from heat for 1 to 2 minutes or until bubbly (watch carefully to avoid burning).