S'mores Rice Krispie Treats

Prepare a 9x13 baking pan with nonstick cooking spray and parchment paper. Extend the parchment paper up the sides of the pan to easily remove the rice krispie treats from the pan.
Spread 10 ounces of the mini marshmallows on a baking sheet pan lined with a silicone baking mat. Broil the marshmallows in the oven for a minute or two until they are golden-brown. Set aside.
In a large saucepan on the stovetop over medium-low heat, melt the unsalted butter. Add the mini marshmallows and toasted mini marshmallows and stir until the marshmallow mixture is melted and smooth. Remove the saucepan from the heat.
Stir in the vanilla extract and salt. Then, fold in the Rice Krispies cereal, roughly chopped graham crackers, and additional 2 cups of mini marshmallows until the cereal is well coated in the melted marshmallow mixture.
Pour half of the rice krispie treat mixture into the prepared baking pan. Moisten your hands with water, and gently press the mixture into the pan creating an even layer. Sprinkle the top with roughly chopped milk chocolate bars. Add the remaining half of the rice krispie treat mixture over the milk chocolate and then gently press the mixture into an even layer.
Press additional graham cracker pieces, milk chocolate bars, and mini marshmallows into the top of the rice krispie treat bars. If desired, toast the mini marshmallows with a kitchen torch.
Allow the rice krispie treats to set up in the pan for 1 hour before removing and cutting into squares.