Measure the ground almonds, coconut flour, glucomannan powder, salt, xanthum gum, baking soda into a bowl. Mix together.
Measure the sweetener, and butter into another bowl then cream together until thoroughly mixed. Then add the egg, and vanilla extract and continue mixing.
Add half the dry ingredients to the butter mix, and continue mixing together until fully mixed in and then add the rest of the dry mix and continue mixing.
If using a chocolate bar, measure out the chocolate then chop into chunks. Add the chocolate to the cookie mix, and mix in.
Either cover the bowl, or transfer the mix to a smaller container which you cover. Then place into the fridge for a minimum of 1 hour.
Preheat oven to gas mark 4/180°C/350°F, and line a baking tray with parchment paper, NOT silicone! Silicone stops it from spreading.
After an hour, remove mix from fridge. Evenly divide the cookie dough into 15 portions. Roll each portion into a ball shape. Place onto the baking tray, and flattern the cookies. The flatter you make them, the crisper they'll be so for super crispy cookies make them really flat. So leave them a bit fatter if you want them less crispy.
Bake in the oven for about 10 to 12 minutes. Bigger/thicker cookies take a bit longer than smaller/thinner ones.