Dust half of the powdered sugar onto the parchment paper.
In a bowl, add the agar agar powder with about ½ cup water.
Gently whisk using a hand whisk, or for this recipe, a standing mixer is really helpful because you have to whisk for a while.
Once the agar agar powder has mixed into the water well, you can put this aside.
In a large saucepan, add the coconut sugar OR the granulated cane sugar and water and bring to a boil. Do not stir. I used a candy thermometer to bring it to approximately 240 F. It takes some time for the temperature to reach this level.
Immediately remove from heat, and using a rubber spatula, pour this mixture into the bowl of the standing mixer. If you do not have a standing mixer, hand whisk in a bowl for about 10 - 15 minutes. Doing it by hand, it took a whole 15 minutes for the mixture to thicken.
Add in the vanilla extract.
Transfer to the pan and let it sit for about 12 hours or overnight.
Once the tops are completely dry, transfer to the fridge for about an hour.
Then score into even cubes. These are ready to go into your s’mores if you are using them in that recipe. If you are making s’mores, these can be made ahead of time and even frozen.