In a large mixing bowl, whisk together all the dry ingredients: almond flour, coconut flour, sweetener, baking soda, xanthan gum.
Pour the melted coconut, unsweetened almond milk (at room temperature or it will solidify the coconut oil), vanilla and apple cider vinegar.
Combine with a spoon at first, then use your hands to knead the dough and form a consistent cookie dough ball. Set aside in the bowl, at room temperature, while you prepare the cinnamon coating.
In a separate bowl, whisk together ground cinnamon and sugar-free crystal sweetener of your choice.
Shape 16 small cookie dough balls. I am using a small mechanical cookie dough scoop to make cookies of the same size and same carb count.
Roll each cookie dough balls into the cinnamon sugar-free sugar, rolling the balls in your hands to stick the coating to the balls. Place each cookie ball onto a baking tray covered with parchment paper, leaving 1 cm space between each cookie.
Flatten the snickerdoodle cookie with a spatula until the sides crack and the thickness is similar to a regular snickerdoodle cookie. These cookies won't expand while baking that is why it is important to shape/flatten them before baking.
Repeat for the following cookies.
Bake cookies at 180°C/355°F for 15-18 minutes or until the sides are slightly golden brown, don't overbake are they won't be as soft.
Remove from the oven and cool down 5 minutes on the baking tray before transferring on a cooling rack. Slide a spatula under each cookie to gently transfer them onto a cooling rack without breaking.
The cookie are soft at first when out of the oven, they will harden and reach their best texture at room temperature, about 1 hour cool down required.