Grease a large saucepan and melt the butter over low heat, releasing a rich, buttery aroma.
Add the marshmallows to the melted butter, stirring constantly until completely melted and smooth. The mixture will bubble gently and become glossy.
Sprinkle in cinnamon and nutmeg, stirring to evenly distribute the warm spice aroma throughout the glossy mixture.
Remove the saucepan from heat and immediately pour in the rice cereal, folding gently with a spatula until the cereal is fully coated with the marshmallow mixture.
Transfer the mixture onto a prepared surface lined with wax paper or a silicone mat. Press it into an even layer with your hands or spatula. Let it cool slightly until just firm enough to handle.
While still warm, carefully shape the mixture into pumpkin shapes or use a pumpkin-shaped cookie cutter to cut out rounds. Gently press facial features into the figures to create fun faces.
Melt orange candy melts or tinted white chocolate according to package instructions until smooth and fluid.
Dip the cooled pumpkin treats into the melted candy, coating them completely, or drizzle the melted chocolate over the shapes for a vibrant orange finish.
Place the coated treats on the same wax paper or silicone mat and let the coating set until firm and shiny. Use icing or chocolate to add eyes, noses, and mouths for character faces.
Allow the decorated treats to sit at room temperature until the coating is completely hardened and glossy.
Enjoy these sweet, crispy pumpkin treats as a festive and fun Halloween snack!
