Preheat oven to 400°F. Mix flour, 2 Tbsp. sugar, the baking powder and salt in large bowl; cut in butter with pastry blender or 2 knives until mixture resembles coarse crumbs. Mix 3 cups of the cereal and the milk in medium bowl; let stand 3 min. Stir in egg. Add to flour mixture; stir just until moistened. (Batter will be lumpy.)
Spoon evenly into 12 greased medium muffin cups, filling each cup 2/3 full. Mix remaining 1/3 cup cereal, 1 tsp. sugar and the cinnamon. Sprinkle evenly over muffins. BAKE 20 to 25 min. or until golden brown. Cool. Makes 12 servings, 1 muffin each.