In a large saucepan, melt the unsalted butter over low heat.

Add the mini marshmallows to the melted butter, stirring continuously until the marshmallows are completely melted and the mixture is smooth.

Stir in the pumpkin puree, pumpkin spice blend, and vanilla extract, ensuring they are well incorporated.

If desired, add a few drops of orange food coloring to achieve a pumpkin-like color. Mix well.

Remove the saucepan from heat and gently fold in the crispy rice cereal until it is evenly coated with the marshmallow mixture.

Press the pumpkin-flavored Rice Krispie mixture into a greased 9x13-inch baking dish, ensuring an even layer.

Allow the Pumpkin Rice Krispies to cool and set for at least 30 minutes.

Optionally, use candy corn and additional marshmallows to create pumpkin shapes on top of the Rice Krispie layer.

Once completely cooled and set, cut the Pumpkin Rice Krispies into squares or desired shapes.

Serve and enjoy these delightful Pumpkin Rice Krispies, savoring the seasonal blend of pumpkin and spice in this fun and easy-to-make treat!