Spray two 8x8″ brownie pans with cooking spray and line with parchment paper both ways for easy removal later.

In a stand mixer bowl with whisk attachment, add the gelatin and water.

Place the agave nectar in a small saucepan (I used a 2-quart pan).  Add a candy thermometer to the pan and place over medium heat. Bring to a boil.  Remove from the heat when the temperature reaches 230°F.

Turn the stand mixer on low speed and slowly and carefully pour in the hot syrup.  Cover the stand mixer with a kitchen towel to avoid any splatters on your counter, and increase the mixer speed to high.  Beat for 3 minutes.

Working quickly, turn off the mixer, add the cocoa powder, charcoal powder, and salt, and turn mixer on medium-low speed.  Mix until both powders are combined, then return speed to high.  Beat for 5 minutes, or until very thick, shiny, and voluminous.

Add the vanilla paste and beat for 1 more minute.

Working quickly, scoop the mixture into the prepared pans and spread it out.  Let sit for 5+ hours, or overnight.

In a bowl, whisk together the starch, erythritol, cocoa powder, and charcoal powder.  Dust your countertop with the mixture.  Gently flip each marshmallow block onto the counter and coat in the starch.  Slice the marshmallows and coat them completely in the starch.  Enjoy!