Spray a mini muffin tin with cooking spray. Melt the Salted Butter (3 tablespoon) in a medium Dutch oven. Add Mini Marshmallows (10 ounce) and cook, stirring regularly, until the marshmallows are completely melted, about 3 minutes.
Turn the heat down to low and stir in the Canned Pumpkin Purée (1/4 cup) and Pumpkin Pie Spice (3/4 teaspoon). Turn off the heat and stir in the Rice Krispies® Cereal (5 cup) and crushed Graham Crackers (1/3 cup).
Grease a spoon with butter or cooking spray, and spoon the Rice Krispie mixture into the wells of the prepared mini muffin tin.
Grease a small piece of parchment and use it to level the top of each bite.
Cover a work surface with parchment. Place a wire rack on top. Loosen the bites with a butter knife and transfer to the rack. Place the chopped Dark Chocolate (1.5 ounce) in a microwave safe bowl and microwave in 15-second bursts, until melted. Drizzle each bite with chocolate.
Let the bites rest at room temperature until the chocolate hardens. Serve them immediately, or store the bites in an airtight container. Enjoy!