Combine powdered sugar, cocoa powder, salt, and cinnamon in a large bowl. Add coconut oil, water, and vanilla extract. Mix until a smooth syrup forms without lumps.
Add flour and baking soda. Mix in with a spatula until completely combined. Mix a couple of extra times to bring everything together.
Create a 1”/2.5cm thick disk out of the dough. Wrap it in plastic wrap and place in the fridge for 10-15 minutes.
Preheat oven to 325° F/160 C. Line baking trays with parchment.
Remove dough from the fridge. Lightly flour both sides of the disc. Between two sheets of baking parchment, roll dough to ¼”/6mm thick.
Use a 2”/5cm round cutter to stamp out as many cookies as possible. If the dough has not warmed too much, remove the excess from around the cookies and transfer them to the baking sheets with 1”/2.5cm between them. If cookies are too fragile, place the cut dough in the fridge while still on the baking parchment for 3-4 minutes before attempting to transfer the cookies.
Using a ½”- ¾”/12-18mm round cutter (or the wide opening of a piping nozzle), cut circles from the center of half the cookies. Use the tip of a knife to remove the excess dough.
Bring all the scraps of dough together and repeat the rolling and cutting process.**
Chill cut dough in the fridge for 4-5 minutes before baking to prevent spreading.
Bake for 14-15 minutes, until dry to the touch. Allow to cool on the pan for 5 minutes before moving to a rack to cool completely.