Preheat oven to broil. Grease a 9x13 baking dish, line a baking sheet with foil, and grease the foil.  

Place the rice cereal and all but ¼ cup (if you can, try to save the larger broken pieces to decorate the top) of the crushed graham crackers. Mix it together well.

Spread half of the mini marshmallows onto the baking sheet and broil for a minute or two. You want the marshmallows to look lightly toasted but not burned. They will burn easily, so keep an eye on them. Set aside. You can turn off the oven for a few minutes while you move on to the next step. 

In a large saucepan, melt the butter. Then, add in the large marshmallows and stir until completely smooth and melted.

Pour the melted marshmallows onto the rice krispies, and scrape the toasted marshmallows in too. Mix well until thoroughly incorporated.

Spread the marshmallow mixture into the greased 9x13 pan in an even layer. Don’t press too hard, or you will have dense bars, and they won’t be as soft and chewy. You may find a greased spatula really helpful for this.

Sprinkle the chocolate chips on top of the bars and place them in the warm oven to melt the chocolate chips. It should only take 20 seconds or so, do it longer if needed. Use the spatula or the back of a spoon to spread the melted chocolate chips into an even layer. 

Turn the broiler back on.

Scatter the remaining mini marshmallows on top of the chocolate and broil for a minute, and then check k it every 20-30 seconds after a minute until it is lightly toasted.  You may also want to rotate the pan halfway through to make sure it browns evenly. 

Once the marshmallows are toasted, arrange the Hershey bars on top of the smores, and scatter the remaining crushed graham crackers.

Allow cooling completely before cutting into the bars. A greased knife will make cutting the bars much easier.