Preheat oven to 350° F.
Melt butter until melted and then stir in 1 cup of crushed cereal, brown sugar and flour until it becomes crumbly. Set aside.
Mix sugar, butter, and eggs until creamy.
Combine flour, baking soda, baking powder, and salt; then add to wet ingredients.
Add bananas and beat until blended.
Pour batter into greased muffin tins or paper cups.
Sprinkle crunchy cereal toppings on top.
Bake for 25 to 30 minutes.