Please read: Measure all of your ingredients out ahead of time. You have to do a couple things at once when making these marshmallows and will not have time to measure as you go. Making marshmallows is very precise.
Line a 9x13 casserole dish with parchment paper. Using a fine mesh sieve, dust the parchment paper with 1/4 cup of tapioca flour. If you want taller, large marshmallows (like in photos), use a 8x10 casserole dish.
Add the cane sugar, light agave, and 1/2 cup of water to large heavy bottom pot and allow to sit for a couple of minutes so the sugar can begin to dissolve.
Once partially dissolved, put the pot over medium heat and allow it to begin to boil. Do not mix this at all or use the lid. Just let it boil.
After the sugar has melted for the most part, add in your candy thermometer so it is reading in the middle of your pot.
When the candy thermometer hits 200-210 degrees Fahrenheit, it is time to start whipping up your Versawhip 600k.
To your stand mixer mixing bowl, add the Versawhip 600k, vegan gelatin, and remaining 1 cup of cold water. Mix this well together so no powder gets stuck to the bottom of bowl.
Begin whipping this Versawhip mixture at medium speed (level 4 on my Kitchenaid Stand Mixer). Make sure to keep an eye on your sugar pot while doing this. We do not want the sugar to exceed a temperature of 240 degrees Fahrenheit. After 3-4 minutes, increase speed to medium high (level 6 on my Kitchenaid Stand Mixer) for final couple of minutes or until mixture has gotten fluffy and reached stiff peaks texture. Turn off stand mixer and set aside until sugar has reached correct temperature.
Once sugar mixture has reached 240 degrees Fahrenheit (soft ball stage), turn off heat and allow some of the bubbles to subside.
Carefully transfer the sugar to a pyrex measuring cup to make pouring the sugar into the stand mixer easier. Alternatively, you can pour directly from pot it is just really heavy.
Resume mixing Versawhip mixture in stand mixer on low and slowly add the sugar mixture by pouring it down the side of the stand mixing bowl. This will take a couple of minutes. You do not want to add it too quickly as the sugar can scorch the Versawhip mixture.
After all the sugar has been added in with the Versawhip mixture, increase speed of stand mixer to medium and mix for 4 minutes.
After 4 minutes, increase speed of stand mixer to medium high and mix for an additional 30 seconds to 1 minute. The marshmallow mixture should be incredibly fluffy and almost to the top of the whisk!
Once finished, using a greased spatula, quickly pour it from the stand mixing bowl into your parchment lined and dusted casserole dish. Spread it so it is evenly filling the casserole dish. You want to do this as fast as you can. The longer it sits, the harder it will be to spread.
Dust the top of the marshmallows in casserole dish with 1/4 cup tapioca flour. Allow to sit and set properly for a minimum of 3 hours.
After 3 hours, remove the marshmallows from the casserole dish. Slice the mashmallows into whatever size you like. I find this easiest to do with a pizza cutter I have dusted with tapioca flour.
Coat each side of marshmallows in remaining tapioca flour. Use more as needed.
Storage: Store marshmallows at room temperature and loosely covered with parchment paper for up to 5 days. Continue to coat them in tapioca flour as needed to keep fresh. Do not store them in an airtight container - they will get incredibly soft and too moist.
Notes
I am sorry but there is no substitute for the Versawhip 600k or Vegan Gelatin. Please only use the two exact brands recommended. Agar agar does not make firm enough marshmallows. I tried it several times.
You must use a candy thermometer. It is too difficult to guess if your sugar has reached the right consistency without one.
I have only made this in a stand mixer but it may work with a hand mixer. Please let me know if you have good results.
If you are roasting these marshmallows, I would coat them in a mixture of tapioca flour and powdered sugar (about 1/3 cup of each). The powdered sugar will help them roast evenly.