Preheat oven to 350°F (180°C). Line a cookie sheet with parchment paper. Set aside.
In a small mixing bowl, prepare the flax egg: stir 1 tablespoon of flaxseed meal in 3 tablespoons of lukewarm water. Set aside for 10 minutes until egg-like texture forms. If not vegan, skip and use a large egg.
In another large mixing bowl, combine almond flour, coconut sugar, cinnamon, baking soda, cream of tartar, and salt.
Add in the flax egg (or egg), melted coconut, maple syrup, and vanilla extract.
Stir until it forms a thick and sticky batter. Gather into a ball and refrigerate for 5 minutes while making the coating.
In another small bowl, make the cinnamon-sugar mixture by combining coconut sugar and cinnamon.
Remove the dough from the fridge, scoop out the cookie dough, and roll between your hand to form balls, then roll them into the prepared cinnamon-sugar mixture.
Place the cookie dough balls onto the prepared cookie sheet. Repeat until you formed 10 cookie dough balls, leaving a 2-thumb space between each.
Press down each cookie ball with the bottom of a glass or your hand until about 0.5-cm thick - see the picture in the post above for tips. The cookie will keep expanding in the oven.
Bake for 12-15 minutes or until golden brown and the middle is slightly firm. The cookies are still soft when out of the oven and firm up when completely cool down.
Cool them down for 10 minutes on the cookie sheet. They are still soft, be patient, and don't touch them!
Gently slide a spatula under each cookie to transfer onto a cooling rack and wait at least 30 minutes to appreciate their best texture.
Store in an airtight container for up to 5 days in the fridge or freeze.
Flour - I didn't try the recipe with any other flour. Oat flour could work, but I guarantee that the recipe won't work with the same amount of coconut flour or all-purpose gluten-free flour. It would be a different recipe to develop.Flax egg - if not vegan, use 1 large egg at room temperature.Coconut sugar - can be replaced with white sugar or unrefined cane sugar. Maple syrup - can be replaced with any liquid sweetener you like including agave, rice syrup.Cream of tartar - can be omitted. It only adds a tangy flavor to the cookies, as in regular snickerdoodle cookie recipes.Coconut oil - don't replace it with vegan butter. The recipe wouldn't work.