In a large mixing bowl, whisk together the brown sugar, Pumpkin Puree , oil, eggs and vanilla extract until well blended.
In a separate medium bowl, evenly stir together the flour, Pumpkin pie spice, baking powder and salt, and then mix this with the wet ingredients until just combined.
With a piping bag or offset spatula, spread about 2-3 tablespoons of Cream Cheese Frosting frosting on the bottoms of the cookies and then sandwich the cookies with the unfrosted halves.