Line an 8x8 inch pan with parchment paper set it aside.
In the bowl of your mixer pour 1/2 cup water in and sprinkle the gelatin over the water, set it aside.
In a large saucepan combine the rest of the water, erythritol, stevia, and salt. Heat over medium heat until all the erythritol has dissolved and small bubbles just start to form on the edges.
Stir in the vanilla to the erythritol mixture.
Turn your mixture to low speed and slowly, carefully pour the hot mixture into the gelatin mixture. Turn the mixer up to high once all the liquid is added. Beat on high for 12-15 minutes, until it makes fluffy peaks.
Pour the mixture into the 8x8 pan and spread it evenly, Place in the fridge for 8 hours, until its firm.
Using a shape knife cut the marshmallows into 1x1 squares.