Get your ingredients and your supplies gathered up.
Grease your pan and your spatula with either butter or non-stick cooking spray
Note: below are instructions for melting marshmallows and butter together in the microwave, if you want to melt on the stove instructions are in the post above.
Place 16 of of marshmallows and 4 tbs of butter into a microwave safe dish.
Heat butter and marshmallows on high for 30 - 60 seconds.
Remove from microwave and stir butter and marshmallows together.
Heat for 30 more seconds.
Remove from microwave and stir. If marshmallows are close to being melted, add in ½ cup of pumpkin puree, ½ teaspoon of vanilla and 1 teaspoon of pumpkin pie spice.
Heat again for 30 seconds and stir well. Stop heating and stirring once marshmallows are completely melted.
Measure 6 cups of rice krispies cereal and add that into you marshmallow and pumpkin mixture.
Fold cereal in completely.
Transfer treat mixture from bowl into greased pan.
Use spatula to lighly press treat mixture into pan.
Set aside to cool for 30 minutes.
Use a knife that has been greased to cut into 16 treats.