Preheat oven to 350°F. Spray a 2 quart baking dish with cooking spray, set aside.
Prepare the pumpkin filling by adding the pumpkin to a large mixing bowl. Add in the spices, stir to combine. Add the eggs and stir until combined. Slowly pour in the milk while stirring. Stir in the flour.
Pour the pumpkin into the prepared baking dish. Set aside.
Prepare the Snickerdoodle topping. Place butter in medium size mixing bowl, mix the butter until smooth and creamy. Add the sugar and cream with the butter until fluffy.
Add in the baking powder, cream of tartar, and salt. Mix until well combined.
Add in the egg and stir until mixed. Add the flour and mix until just combined.
divide the dough into about 12 equal pieces. Roll each piece of dough into a ball using the palms of your hands. Then slightly flatten so they look like round disc shapes.
In a small bowl stir together the coating by mixing the sugar and cinnamon. Dip each rounded piece of dough into the cinnamon/sugar coating. Coat both sides of the dough. Place the cookie dough onto the pumpkin filling in an even layer.
Bake for 35 minutes or until the filling is set, it will start to pull away from the edges of the baking dish.
Set aside to cool about 10 minutes.
Serve warm with whipped cream or ice cream! Enjoy!