Place marshmallows in a single layer on a parchment lined baking sheet. Place in the oven under the broiler and broil about 5 minutes, watching constantly, just until the marshmallows turn golden brown. You may need to move your pan around to get all of the marshmallows directly under the broiler depending on your oven.

Remove from the oven and set aside.

In a large sauce pan, heat the butter over low heat until fully melted. Add the roasted marshmallows to the pot and stir with a wooden spoon until the marshmallows are completely melted. Turn off the heat.

Add the cereal to the pan and stir to coat in the marshmallow mixture. When cereal is fully coated, stir in the mini marshmallows and chocolate chips. Stir again to distribute.

Press the cereal mixture into a parchment lined 9x13 baking dish and let sit until completely cooled and firm. Cut into bars and serve.