Combine the almond flour, coconut flour, baking soda, cream of tartar, salt and cinnamon in a medium mixing bowl and whisk until combined.
In a large bowl, cream together the coconut oil or butter and sugar until smooth and fluffy (if you’re using butter), about 2 minutes. Beat in the egg and vanilla and mix on medium until well combined, another 2 minutes, scraping down the sides of the bowl as needed.
Slowly add the dry ingredients to the wet until fully combined and a dough forms. Cover and chill dough for at least 30 minutes before rolling into balls and dipping in cinnamon sugar).
While the dough is chilling, preheat oven to 350°F and line a large baking sheet with parchment paper. Set aside. Once dough is chilled, combine cinnamon & sugar in a small bowl. Use a large tablespoon to form dough into 18-20 balls and roll each one in the cinnamon sugar topping. Place on cookie sheet and flatten using the bottom of a cup or your hand.
Bake in the preheated oven for 9-11 minutes or until cookies are set on top. Allow cookies to cool slightly on baking sheet before transferring to a wire rack to cool completely.