Line a 9x13-inch baking dish with parchment paper. Make sure the parchment extends up the sides for easy removal. Then, spray the parchment with baking spray.
To a small bowl, add ¾ cup Golden Grahams cereal, ¾ cup miniature marshmallows, and ¾ cup chocolate chips. Mix to combine. Set aside to use for the topping.
In a large saucepan over medium-low heat, melt the butter.
Add 8 cups of miniature marshmallows to the melted butter. Stir constantly for about 3-4 minutes, until fully melted and smooth. Remove from heat.
Immediately stir in the remaining Golden Grahams cereal, making sure it is fully coated.
Quickly fold in the remaining miniature marshmallows and chocolate chips, stirring gently to combine. Avoid overmixing so the chocolate doesn’t melt too much.
Press the mixture evenly into the prepared baking dish.
Sprinkle the reserved cereal, marshmallow, and chocolate mixture over the top, pressing it down gently to help it stick.
Let the bars cool completely in the pan (1-2 hours).
Once set, lift them out using the parchment paper. Cut and serve.