1Heat oven to 375°F. Spray bottom and sides of 8-inch square (2-quart) glass baking dish with cooking spray. Place cereal in resealable food-storage plastic bag; seal bag and slightly crush with rolling pin or meat mallet. Set aside.
2In large bowl, mix brown sugar, flour, lemon peel, cinnamon and nutmeg. Stir in rhubarb and blueberries. Spoon into baking dish. Sprinkle with crushed cereal and pecans.
3Bake 30 to 40 minutes or until rhubarb is tender when pierced with a fork. Let stand 30 minutes before serving.