In the bowl of a mixer, add butter and cream cheese and mix on medium speed until well creamed, light in color, and blended.
Add in the powdered sugar, heavy cream, vanilla, and pumpkin pie spice and mix on medium speed until the frosting is smooth and creamy.
Add food coloring if desired, and mix well. Add more pumpkin pie spice or cinnamon for a speckled color if there isn't enough for the look you want. Use a tablespoon of cocoa and a drop of brown coloring for a rich dark brown color.
Place piping tips into piping bags and fill with frosting with star tips I used a 2D and 4B tip for these pumpkin cookies.
Be sure the cookies are completely cooled before frosting, once frosted place the trays of frosted cookies into the fridge to firm up the frosting until completely cold. I avoid stacking cookies with cream cheese frosting, and when wrapping them in plastic bags, I leave a little air in the bags so the bag doesn't touch all the frosting to avoid it messing up the frosting.