-
Choose your desired size baking pan (for thicker bars use a 9x9, for thinner bars use 11x7 or 13x9) and spray generously with nonstick cooking spray.
-
In a large saucepan, melt butter over medium heat. Stir in pumpkin puree and cook until warmed through. Fold in marshmallows, stirring frequently until melted. Remove from heat and stir in vanilla, cinnamon, nutmeg, and salt.
-
Let marshmallow mixture cool at room temperature for 20 minutes. Add the crispy rice cereal and stir until combined.
-
Pour mixture into prepared baking pan, spread out evenly and gently press down with a rubber spatula or greased fingers. Refrigerate to set for at least 1 hour. Sprinkle with fall colored sprinkles (optional).