In a large bowl, add all of the dry ingredients, and whisk to blend.
In a small bowl, add all of the wet ingredients (egg, pumpkin, vanilla, and coconut oil) and mix well.
Pour the wet ingredients into the dry ingredients and mix.
Use a cookie scoop to drop dough onto the baking sheet.
Use a clean hand to flatten and shape so all of the cookies are the same size.
Bake 8-10 minutes until done.
When the cookies are cool, add frosting to one cookie and put another cookie on top to make a sandwich.
I have tested this recipe with King Arthur Measure for Measure GF, Bob's Red Mill 1 to 1 GF blend, and Authentic Foods Multi Blend in this recipe. That doesn't mean others will not work, I just have not tested other flours.
If your gluten free flour blend doesn’t contain Xanthan Gum or Guar Gum, please add 1 teaspoon.
Note, you can substitute brown sugar for coconut sugar and butter instead of coconut oil.