Crush whole 6 oz gingersnap cookies in a plastic Ziploc bag. Then grind the cookies into a finer powder.
Melt ½ stick butter in a small bowl and add cookie powder to melted butter. Press the crust into a tart pan and set it in the refrigerator.
Marshmallow Pumpkin Filling
In a medium saucepan, heat all filling ingredients (4 oz marshmallows, 1 cup pumpkin puree, 8 oz cream cheese, ½ tsp Pumpkin pie spice, ½ tsp vanilla extract) over low heat. Be sure not to burn marshmallows, so stir often.
When melted, take off the heat and stir for a few minutes to cool down.
Take crust out of fridge and pour filling level into tart pan. Put tart into the fridge for at least 4 hours.