In a large mixing bowl, cream the butter and sugars together. Add in the large egg yolk, vanilla, and pumpkin puree and mix well. Then slowly mix in coconut oil.
In another small bowl, whisk the flour, salt, baking soda, cream of tartar, cinnamon, and spices together. Add the dry mixture into the pumpkin mixture and combine.
Line cookie sheets with a cookie mat, parchment or spray with cooking spray. Scoop 2 Tablespoons of cookie dough and roll into balls. Place 2 inches apart on cookie sheet and slightly press down with the back of a wooden spoon or your hand to 1/4 inch thickness.
Bake at 350 degrees for 10 to 12 minutes. Cool on wire rack.
Cream Cheese Frosting Directions
With an electric mixer, beat cream cheese, butter and vanilla together on medium-high speed until smooth. Gradually add in the powdered sugar until it is all combined and the frosting is smooth. If it is too thick, add in a tablespoon or two of milk (or water) until it reaches your desired consistency. If it is too thin, add in more powdered sugar until it reaches your desired consistency.
When the cookies are completely cooled, spread the frosting on top of each cookie.