In a large mixing bowl, microwave the butter
Mix in the Marshmallows with the butter until melted.
Stir in the pumpkin puree and pumpkin spice.
Add rice creal and stir.
Grease a dish or add rice krispie mixture to parchment paper. Use a spatula to flatten the treats. Let the treats cool for about 30-minutes before cutting into them.
Top with candy corn! ** optional **