Grease a 9x13 pan with cooking spray

Using your hands, crush 3 cups of the Golden Graham cereal into a bowl. Add remaining cereal to the bowl.

In a saucepan over medium heat, melt the butter. When the butter is melted, stir in 1 1/2 bags of mini marshmallows. Stir until barely melted.

Pour marshmallow mixture over cereal. Quickly add chocolate chips, remaining mini marshmallows, and marshmallow bits, if using. Stir gently until evenly mixed.

Press mixture into pan. Top with segments of Hershey bars, pressing gently into the bars so they will adhere. Allow bars to completely cool before slicing and serving.