Combine first 5 ingredients in small bowl, mixing until crumbly. Cover tightly and store overnight for topping.
Stir together the 1-1/2 cups cereal, flour, baking powder, soda, salt, cinnamon and sugar in large mixing bowl. Add buttermilk, shortening and egg. Beat until well combined. Spread batter evenly in greased 9x9x2 baking pan. Cover tightly. Refrigerate overnight.
Morning--Remove pan from refrigerator. Uncover and sprinkle topping over batter. (first 5 Ingredients)
Bake in oven at 350* about 25 min. or until tests done. Cool 5 min. before serving