Preheat oven to 350 degrees and prepare a cookie sheet with parchment paper or a Slipmat.
For the cookies, mix the dry ingredients together; spices, baking soda, baking powder, salt and flour. Set aside. In a mixing bowl, whip together the pumpkin, I Can't Believe Its Not Butter Stick and sugars. Once well mixed, add the egg and vanilla. Add the dry mixture to the wet slowly.
Using a small cookie scoop, place dough on cookie sheet; spaced about 1 inch apart. Bake for 10-12 minutes. They will puff up and shouldn't expand horizontally very much.
Let cookies cool on a wire rack until completely cool before filling.
Creme Filling
In a stand mixer, whip together the butter and the marshmallow fluff, the vanilla and the confectioners sugar.
I used a Wilton 1M tip, and filled a piping back with creme filling. I piped a glop in the middle of a cookie and then sandwiched another one on top.
Store covered in the refrigerator for up to on week.