In a large Dutch oven or saucepan, melt butter over medium low heat.

Once melted, add pumpkin puree and pumpkin pie spice and stir until combined. If using, add few drops of orange food coloring for a more vibrant shade. You'll want it to look a bit darker than you want the final product to be since the color will lighten with the addition of marshmallows and rice krispies cereal.

Set aside 1 cup of the mini marshmallows and add the remaining marshmallows into the saucepan and stir until completely melted.

Remove from heat, then stir in vanilla extract.

Add rice krispies cereal and the remaining cup of marshmallows. Stir to gently combine.

Let this mixture cool slightly until it's cool enough to handle with your hands. Line a baking sheet with parchment paper.

Lightly wet your hands with water to keep from sticking, then scoop about ¼ cup (I used a large cookie scoop). Shape into a ball with your hands (make sure not to pack too tightly), then place in a single layer on the parchment line baking sheet without touching each other.

Insert a pretzel stick into the center and reshape if needed. Add green M&Ms next to the pretzel sticks for the "leaf".

Cool for an hour to set, then enjoy!