Prepare the Base:

• Line a baking sheet with wax paper and grease it with cooking spray.
• In a pot over low heat, melt the butter. Add mini marshmallows and stir until fully melted and smooth.
• Turn off the heat and immediately stir in Rice Krispies cereal until well coated.
• Press the mixture onto the prepared pan into a thin, even rectangle.

Add Toppings:

• Spread marshmallow Fluff evenly over the cereal base in a single layer.
• Sprinkle crushed graham crackers over the Fluff, pressing them gently into the Fluff.
• Pour the melted chocolate over the graham crackers, spreading it into an even layer with a spatula.

Roll and Chill:

• Slice the layered sheet in half lengthwise.
• Roll each half starting from the long side, similar to a sushi roll.
• Refrigerate for about 1 hour or until firm.

Serve:

• Slice the rolled-up mixture into sushi roll-sized pieces.
• Serve with additional melted chocolate on the side for dipping.