Pre-heat the oven to 400f/200c. Grease an 8 inch circular cake pan or skillet.
In a bowl, mix together the pumpkin puree, cream cheese, sugar and cinnamon (or pumpkin spice). Beat until smooth then spread in an even layer in the cake tin.
Scatter over chocolate chips. Then top with marshmallows - make sure there are a good amount on top, but you don't need to fully cover the filling as the marshmallows will spread A LOT in the oven - leave gaps between each.
Bake 8-10 minutes, keeping an eye on it and removing from the oven when the marshmallows look toasted and golden! Remove and serve immediately with graham crackers/digestive biscuits or other cookies of your choice!