Put 3 cups of your graham crackers or cereal into a gallon baggie. Zip to close. Smash them until they are fine, empty into a bowl.
Melt your butter and pour it into the bowl with this, stir until well combined.
In another bowl put your cream cheese (make sure it's room temperature) and approx 3 tbsp. of canned pumpkin puree.
Use a mixer on low speed to create a smooth pumpkin cheesecake mixture. Do not over mix, it will be thick. Then gently fold in your marshmallow creme.
Spoon cheesecake mixture into a pint size freezer bags or a pastry bag with a tip and place into the fridge for about an hour so it hardens more.
Put 2 heaping tbsp. of your graham cracker crumbs into each mini mason jar and pat down with the back of your spoon.
Snip the corner of your freezer bag off and squeeze a swirl of your pumpkin cheesecake mixture on top, followed by another layer of 2 heaping tbsp. full of crumbs.
Squeeze one more layer of no bake pumpkin cheesecake mixture on top of that and sprinkle with cinnamon and nutmeg if desired. Enjoy!